Consider expected behavior on each platform

The first step is to spend some time considering what
the expected appearance, presentation, or behavior is on this platform.
Try to forget any limitations of your current implementation,
and just envision the ideal user experience.
Work backwards from there.

Another way to think about this is to ask,
“How would a user of this platform expect to achieve this goal?”
Then, try to envision how that would work in your app
without any compromises.

This can be difficult if you aren’t a regular user of the platform.
You might be unaware of the specific idioms and can easily miss
them completely. For example, a lifetime Android user will
likely be unaware of platform conventions on iOS,
and the same holds true for macOS, Linux, and Windows.
These differences might be subtle to you,
but be painfully obvious to an experienced user.

Find a platform advocate