There's an absolute TON over at MobilityWOD
I'm not a fan of the thought of having a flexibile lower back. It should be tight, it's meant to be upright. Others will probably disagree, and I'm not sure what KStarr thinks about it (honestly never looked into low back, I've never had issues).
As for hips, some of the ones I like are banded scissor/lunge position for anterior hip capsule, exploring the depths and regions around a front foot elevated jerk position, and a few others. More squats will definitely help you become more mobile for that specific movement.