What the title says
Once you know the syntax and how to use it, the best thing to do is pick something simple and try and make it. It doesn’t have to be something revolutionary/never been done before. Find a simple addon that you would normally find on garrysmod.org, and try and make your own version. Hint: start reeeeeeeeally simple.
What sort of things are reallllyyyy simple, though?
There have been like 100’s of threads like this one with the same question
Not to mention the very TOP one.
It has everything you’ll need. Good luck.