Thread:Talk:Universal Language Selector/Buggy implementation of ULS in commons/reply (15)

On the general procedures, you can see there's a lot of work going on: Language Testing Plan. You can help by describing test that should be performed regularly, I think: see Quality Assurance/Browser testing/How to contribute.

For specific issues, however, it's simple, for all users: even if you don't plan to help systematically, you can be of great help if you just use the tools normally and immediately report the problems you find, being focused (specific and detailed, not vague or offtopic): see How to report a bug.