Please read and apply https://wiki.eclipse.org/User_Interface_Guidelines#General_UI_Guidelines(actually that whole document, including the referenced platform guidelines).
I know the document is partially outdated, and like every guideline, it
will never be complete. But it still contains the essentials that should
be followed unless you have good reasons to deviate (in that case, document
the reasons in code or in the bug).
I can't correct all your contributions,
so please apply these guidelines yourself.