My #1 tip? Get out a move around with that rig. Hike for miles and miles. Take notes as you go. No load out survives first contact with the trail!
And don't just walk around. Bend, jump, reach, run, fuck around in general. I won't put up with even a tiny annoyance as that annoyance will get magnified 7 fold in the field. This sounds doofy, but I wear a new rig around the house for an evening, shakes a lot of the bugs out before you even leave the house.