TEXT: Heavy Metal
  This appears difficult at first but it's really not. Follow along closely and I'll show how
  easy it is to make an object appear Metalic.
  Step 1: 50% Grey
  Whatever your object is..start with a flat fill of 50%
  grey
  Step 2: Selection Samba
  1) Using the rectangular Marquee tool Make a
  "banded" selection horizontally across the object.
  Hold down shift and creat several more marquee 
  selections of varying size across the object. 
  2) "feather" the selections by 5 pixels (keyboard
  shortcut alt+ctrl D ..cmd+opt D for mac users)
  3) Open the levels dialog box(ctrl L) and increase 
  the black output slider to about 64. Click ok.
  4) with you keyboards arrows. move the selection
  down about 8 taps and invert it (ctrl+i)
  Step 3: Double check
  Your object should look something like this now.
  You can probably get the same effect by holding
  shift and airbrushing dark bands across the object.
  It's up to you...just make sure the object is all
  greyscale and banded like you see here.
  Step 4: Bevel it
  If you have Photoshop 5 or higher. Add a bevel
  using layer effects. Once you have created the 
  bevel...make a new blank layer beneath the object
  and merge the object layer down with the blank
  layer...this fuses the effect to the object so we can
  do step 5.
  If you are using eyecandy...just make a nice bevel
  and join us on step 5.
  
  Step 5: Curve it
  Here's the magic. With your object layer selected.
  Open your curves dialog box (keyboard shortcut 
  ctrl+M) and make a curve kinda like you see here.
  Just click on the diagonal line and drag up and
  down. 
  Step 5: Double Check 2
  You should now look something like this. Neat eh?
  but it's still missing a little something.
  Step 5: colorize it 
  Hit Ctrl+U to bring up your hue & saturation dialog
  box. Click on the "Colorize" box on the lower right
  and slide hue to about 225 and saturation down to 
  about 15. This will make the metal kind of blueish.
  You can color it however you want though.
  Click OK
  Step 6: sharpen it
  I know the filter is called "Unsharp" but it does just
  the opposite. Run the filter with settings similar to
  what you see here and it will make the darker parts 
  of the chrome "pop" out a bit and lend an air of
  realism to the whole effect.
  
  Step 7: drop shadow and completion
  There ya go! A drop shadow...maybe a few
  lensflares and you have a cool chrome object and
  you never had to resort to a 3D application.
  Rain
  I just posted this as a response on Megatokyo's board...figured it was valuable enough
  to post here as an effect tutorial.
  Step 1: Have a source pic
  Make sure you got something to rain on...not
  really a step 1 but I had to start somewhere.
  Step 2: Make some noise
  Create a new layer above the background
  layer and fill it with black. 
  Run Filter>Noise>Add Noise
  Choose: Gaussian, Monochrome and an 
  amount of around 65..depends on how big
  your pic is and how much rain you want.
  Step 3: Motion Blur
  Now...run a motion blur filter
  >Filter>Blur>Motion Blur
  Use a setting similar to what I have here.
  Change the layers blending mode to "Screen"
  (That makes all the black transparent)
  Now do this:
  >Image>Adjust>Levels
  Slide the central grey arrow to the right till
  the rain looks right. 
  
  Step 4: Tada
  Now you have rain! Easy!
  Add to it's realism by adding puddles and
  reflections on hard surfaces..make little white 
  "v"s where the rain bounces off stuff in the
  foreground.
  Smoke
  How to make a smoking Gun, Cigarette...whatever. EASY!!
  Step 1: Choose your smoking object
  In this case...it's a gun...now I know guns only smoke
  for a second after you shoot them but there are certain
  liberties the entertainment industry takes with
  physics...like spaceships making rumblesounds and
  firey exposions in the vacuum of space. Smoking guns
  just add drama to a picture.
  Step 2: Airbrush
  On a new layer..Airbrush some grey over the origin of
  the smoke. Use a soft brush setting and a lower
  opacity.
  Step 3: Spatter fun
  Now we need some "pepper". Change you airbrushes
  setting to "dissolve" and shoot some white and black
  particles onto the grey spot. Not too many...just
  enough to smear
  Step 4: Smudge
  Grab the smudge tool (looks like a pointing finger) and
  smear the pixels upward in an "S" like motion. Don't
  worry if the effect is too severe right now...just smooth
  it all out.
  
  Step 5: Finishing Effects 
  Grab your eraser tool and set it to airbrush with a soft
  brush setting and trim out the unwanted smoke. Use
  the dodge and burn tools to add highlites and shadows
  to the smoke. Re-smear any pixels or effects that look
  "too hard"
  Lower the smoke layers opacity to taste.
  Neon Sign
  Neon signs are also really easy to make in Photoshop 5. I'll show you both ways in
  case you have an earlier version.
  Step 1: make it dark
  Your background
  should be dark and 
  use colder nightime
  colors.
  Step 2: Pick a round
  font
  Neon signs are 
  basically bent tubes
  filled with glowing gas.
  There aren't any sharp
  corners so pick a font
  the has rounded 
  edges. I usually make 
  the font color white.
  The NEON colors are 
  produced by the filters 
  in the next few steps.
  Step 3: Layer Effects
  If you have photoshop
  5 or higher you can do
  it this way. Don't fret if 
  you dont..i have
  alternative steps listed 
  below.
  Make your settings
  similar to what you see
  here. Do this for both 
  Inner and Outer glow.
  Make sure you use the
  same color.
  
  Step 4: Add a drop
  shadow
  Add a drop shadow
  and call it good. 
  Maybe airbrush some 
  of the signs color onto
  the wall it's attached 
  to.
  Alternative step 1
  Type your text. Only 
  this time..instead of
  white, use the color 
  you want the neon 
  sign to be.
  Alternative step 2
  Select the text 
  (cntrl-click the layer 
  the text is on).
  Contract your 
  selection by a few 
  pixels. Feather the
  selection by a few 
  pixels and create a 
  new layer..fill the
  contracted, feathered 
  selection with white.
  Alternative step 3
  Now..go back to your 
  base neon color layer 
  and apply a gaussian
  blur to it. Make about 3
  copies of this blurred
  color layer to enhance 
  the effect.
  
  Alternative step 3
  Now add a drop 
  shadow and airbrush 
  some of the neons
  color onto the 
  background layer to 
  make it believable.
  There's a few extra 
  steps to this 
  alternative method but 
  the results are a little
  more realistic. Try this 
  technique with
  outlined text.
  Fire/Plasma Ball
  Fireballs are really easy but it's best if you have a WACOM tablet so you can take
  advantage of its pressure sensitive features.
  Step 1: make a ball
  Make a white ball on it's own layer...easy
  Step 2: Make a glow
  I don't use Layer effects for this. I make a copy of the ball.
  Select it...expand the selection by 5 pixels..feather the
  selection by 5 pixels and fill it with orange or a good fire color.
  I then merge the original white ball onto the orange glow I
  created...should look like this.
  Step 3: Get to smudgin'!
  I start with a larger brush setting and softly drag from the
  center out. I then choose a smaller brush setting and make
  the little wisps you see around the edges. If this was blue it
  would make a nice Plasma ball. The Wacom tablet allows me
  to control where the wisps fade out. If you don't have a wacom
  tablet you may have to go back in with the eraser tool and
  taper off the wisps manually. If you smear the ball in one
  direction only you can add the illusion of motion.
  Give it a try!
  
  Power Blast
  I get a lot of questions on how to make energy bolts like they use in Dragonball or in
  StarBlazer (Wave Motion Gun..YEAH). Here's a recipe for a cracklin' energy blast you
  can use to destroy things with.
  Step 1: Choose your source
  The blast has to come from somewhere. I put a
  circle here for tutorial purposes but you just pretend
  it's a gun muzzle or someones hand, k?
  Step 2: Make the base of the bolt
  Use the polygon lasso tool and click out a blast
  beam selection in perspective like you see
  here.Make sure it's on it's own layer. Fill it with a 
  good bolt color...light blues, purples, greens and
  reds are good. Make sure it's a bright color high on
  the saturation.
  Step 3: Getting in touch with your inner bolt
  Now...create a new blank layer above the outer bolt.
  ctrl+click on the outerbolt layer to make the bolt a
  selection. Contract this selection by a few pixels
  and fill this new contracted selection with white on
  it's own layer. You should now have something like 
  you see here.
  Step 4: Blurry
  Apply a gaussian blur to each layer. Play with the
  settings..I used a 2.5 pixel blur...you may need less 
  or more depending on the size of your picture. 
  This technique also makes a good light saber.
  Step 5: snap, crackle, pop
  On another new blank layer, grab your paintbrush,
  set it to 1 pixel, 100% opacity, normal
  blendingmode and brush out some lightning forks 
  along the beam.
  
  Step 5: Glow
  If you have photoshop 5 or higher you can apply the
  "OuterGlow" layer effect to the lightning layer. Use 
  the eyedropper to select the outer glow color from
  the beam itself. 
  TaDa. 
  If I was actually using this in a pic I'd probably
  sharpen the beginning of the beam a little and add a
  lensflare or muzzle flash to the origin.
  Displacement Maps
  Displacement Maps
  are useful for 
  making 2D patterns
  "wrap" around fold 
  or curves on an
  object with a 
  perceivable depth.
  I was studying
  Intron Depot 2 and 
  noticed Master 
  Shirow uses
  displacement maps 
  a lot when texturing
  clothing or 
  monsters. 
  I'm no master 
  Shirow and this art 
  to the left was a bit
  rushed but 
  hopefully it will be 
  enough to help you 
  unlock the secrets
  of this advanced 
  photoshop
  technique.
  
  First...prepare your 
  lineart like I've 
  shown you in past
  tutorials on 
  coloring.
  Place the lineart on
  it's own layer and 
  change it's blending
  mode to "Multiply".
  This will allow you
  to paint and work 
  on layers 
  underneath the line 
  art without painting
  over or obstructing 
  the lineart.
  Basically, "Multiply" 
  makes white 
  invisible whereas
  "Screen" makes 
  Black invisible
  Color in the
  portions that will not
  be affected by the 
  displacement map. 
  In this pic I just plan
  on adding patterns 
  to the Kimono, OBI
  and Fan.
  I've already chosen 
  my pattern and 
  used the
  eyedropper to grab 
  complimentary 
  colors from the 
  pattern so the
  Kimono's trim will 
  look nice with it 
  when I apply it.
  
  Create a new layer
  above your color 
  layer and below 
  your lineart layer. 
  Name it "Pattern"
  so you know what it
  is later.
  Find a pattern on
  the net or scan one 
  in that you like. Fill 
  the entire layer with
  this pattern.
  Hide your pattern
  layer by clicking the
  EYE off.
  Switch to your
  channels pallete , 
  Create a new 
  channel and mask 
  out the part of the
  drawing you want to
  apply the pattern to.
  (Paint the area
  white)
  If you see only 
  black, make sure 
  you click the "EYE"
  on for the RGB 
  channel. Your new 
  Alpha channel 
  should then be 50%
  red so you can see
  what your painting 
  over.
  
  Make a copy of the
  channel you just 
  masked out and 
  begin shading it to
  match the light 
  source you've 
  established in your 
  picture. Apply a
  Gaussian Blur of a 
  few pixels when 
  you have it shaded 
  the way you like it.
  Copy this channel 
  (select all, COPY) 
  and paste it into it's
  own document. 
  (ctrl+N , ctrl+V). 
  Make sure the new
  document's mode is
  set to "Grayscale"
  Flatten the new
  document and save
  it as 
  "displacement.psd"
  
  Go back to your
  main art document 
  and make the 
  "Pattern" layer 
  active by clicking on
  it.
  Go to your filters
  menu and choose 
  "Distort>Displace"
  Choose the default
  setting of 
  10,10..repeat edge 
  pixels. Click OK and
  browse to the
  "Displacement.PSD"
  document we 
  previously saved. 
  Click OK.
  Now your texture is 
  "wrapped" around 
  the folds and curves
  we shaded. If the 
  effect is too 
  strong..undo the 
  filter and redo it with
  a lower setting like 
  5,5 or so.
  Use the mask
  channel we made 
  that doesnt have 
  shading to select 
  the textured area.
  Invert the selection 
  and trim away the 
  excess pattern.
  Now the pattern is wrapped but still requires some shading. Use the dodge tool to add
  highlights in the appropriate areas. Repeat this process for any other areas you want to
  wrap a pattern around. Go back to page 1 to see the completed version of this piece.
  
SOURCE: textdata/thevault/Crafts/Design/Cartoons  Comics  Fantasy/How to Draw Manga/How to Draw Manga - Photoshop Techniques.pdf