(If you don’t cheat on your taxes, this thread is not for you. Go brag or scold elsewhere! This thread is for us admittedly lost souls who don’t do it right, but have our reasons.)
I mainly do it to simplify. I could list as income all those little interest slips from the odd savings account interest, but it’s a lot of bother and wouldn’t change the tax more than a few dollars, so I just toss them out.
But mainly I take money that I could deduct if I filled out a bunch of forms and just don’t file those, but instead overestimate the things that they can’t easily check, like charitable donations.
So I don’t tax dodge really, but paperwork dodge.