This morning's git explanation, and I quote:

"lalala... lala... lalala"

Someone got laid I think.

What would be the best tips for keeping code clean?

I recently noticed how "unclean" my code is, I try to organize it as much as possible but through that I manage to make the code very messy :/
What are your best tips, advise, tricks... lalala?

Note:
This problem mainly applies to long projects and games :P