I started out bringing the whole house with me and it got frustrating. It got to a point where I would leave my tackle in one place... Stopped that when my line broke and everything was on the other side of the pond. As some said, you'll start leaving things that wasn't used during your trips. I've narrowed it down to 1-2 Plano 3650's and around five bags of soft plastics (depending on pond).
Box 1: Hooks, sinkers, top water lures, spinner bait, crank bait, pliers, scissors
Box 2: Lizards, ribbon tail worms, craws, senkos (multiple colors of each) Individual soft plastic packs include: Flukes, trick worms, and frogs
Soon, I'll get a bigger Plano and transfer some things so that there will be no separate packs of soft plastics to carry around and it'll be two Plano boxes only.