I acquired a Polaroid SLR 680 this week and I’m in love! Any tips or advice on mastering this amazing camera?

That is my favorite! Honestly its going to do a lot of the work for you. Its an amazing well made camera. You don’t have much exposure control, but generally speaking give it about 1/3 of a stop adjustment on the front to help in extreme light situations; if you’re not good about remembering to adjust it then just leave it centered.