Lie with your upper back, neck and shoulders supported by a swiss ball. Let your hips bend and drop your bottom down towards the ground (try not to let the swiss ball move). At the bottom of the dip slowly tilt your pelvis to get a neutral spine. Push down through your heels and then increase the heel push and squeeze your buttocks to raise your pelvis off the floor back into your starting position. Don't let your lower back arch during the raise or at the top of your lift, keep your lower back in a neutral position. Pause and hold the glutes squeeze and then repeat.

Put a band around your legs just above the knee to and resist outwards to increase your deep glute activation.
For more load put weight across the front of your pelvis. (You must get your technique right before adding weight).