LPT: Always keep your receipts from any merchant (restaurants, stores, etc) that has a separate receipt to add a tip....unfortunately tip fraud has gotten way worse for me in the last few weeks.

3 times in the last few weeks I've caught an additional tip being added on to what I wrote. I get made fun of for it, but I actually keep the duplicate receipt they give you and write what I wrote then for this purpose. It's my fucking money and more on principle that makes it worthwhile.