I'm going to leave a note for my neighbor regarding his trash
Why would you leave him a note about his trash?
I want him to stop leaving his trash everywhere because it is bad for the environment.
That makes sense. It's fine for you to let your neighbor know how you feel about how he handles his trash.
I'm just going to throw it everywhere and make him pay for it.
You shouldn't throw the garbage around and make it worse. Just talk to him about his trash and I'm sure he'll understand.