Start lighter than you think on RDLs and hip thrusts. Once you can complete all sets without feeling it in your lower back (vs glutes/hamstrings), then add weight. Check footwear — worn-out or zero-drop shoes can cause pelvic tilt compensation.

When an exercise gets easy, slow the tempo before going heavier: 3s up, 2s hold, 3s down. This extends the challenge of each weight before needing the next DB up.

Watch the tutorial videos for: Romanian Deadlift, Single-leg Deadlift, and Bulgarian Split Squat. These have the most technique nuance and are most directly relevant to fixing back pain.