This made me laugh, because I feel like you’re answering your own question!! There is no other, or better key to organizing a closet than getting rid of what’s not needed! It can help to set a goal for yourself to get it done in increments — hang a few things back up each time you’re in your room, etc.
If the one clothing bar isn’t enough in your one closet, there are lots of inexpensive shoe racks and drawer systems you can get to add additional storage options. But I promise it’ll be much easier to figure out what you need after you get rid of the clutter! To my mind, it sounds like one closet should be clothing storage, and the other should be shoes and accessories.
Hopefully this helps! Good luck with your closets!