I tried a new post-chain exercise yesterday(new for me anyway). I have a sandbag made of an army duffel bag and 150 lbs. of sand. I get the sandbag in a bear hug near the bottom, to maintain grip easier, and then perform a goodmorning/pullthrough type movement.
4 sets of 8 after ME good mornings and rack lockouts were plenty. My lower back is sorer than a mofo today, but a good sore.