What are your favorite small home office organization tips that made the biggest difference?

I've been improving my small home office recently, and a few simple changes made a huge difference. Wall shelves, cable management, desk organizers, and under-desk storage helped keep my workspace much cleaner and more productive.

I'm also collecting ideas from others.

What's the one home office organization tip or product that has made the biggest difference for you?

I recently put together a guide with 25 practical ideas after trying different setups. If anyone is interested, I'll share the link in the comments.