Find a platform advocate

If possible, assign someone as an advocate for each platform.
Ideally, your advocate uses the platform as their primary device,
and can offer the perspective of a highly opinionated user.
To reduce the number of people, combine roles.
Have one advocate for Windows and Android,
one for Linux and the web, and one for Mac and iOS.

The goal is to have constant, informed feedback so the app
feels great on each platform. Advocates should be encouraged
to be quite picky, calling out anything they feel differs from
typical applications on their device. A simple example is how
the default button in a dialog is typically on the left on Mac
and Linux, but is on the right on Windows.
Details like that are easy to miss if you aren’t using a platform
on a regular basis.