Taking Dan Heisman's advice in Novice Nook 81 (item #12), I am starting a 'book' of positions where I erred. They will likely be flat out material losses in many cases. Until I improve, what else would they be- poor attack of an isolated pawn? Nope (see item #14).
The article was also a good bump for reinforcing why I need to do all the mate in ones in PCT...not so much for me to see them, but rather to see them in replies my opponent may have.
So- mistake number one.
Up a Queen for a Knight, I played 20. ... Rxc2. I still won, but it was a lot harder than it needed to be.
Should have played ... Rxe5, with threats of mates or getting another exchange.