I’ve done something similar, but I find when it comes to hips, crab pinching with my index finger and thumb gets the best reaction, especially focusing right on the fleshy spot between the hips and lower ribs, Also love focusing on the waistband of a person, nothing quite like the very slow dragging of finger nails or with guitar picks, travelling very slowly from the person left side to their right, and keeping an eyes on their facial expressions as you move yours fingers along this spot, it always brings a grin to my face, every time, also the waistband/pantie.line/lower tummy really is one of those spots you can experiment with, alternating speeds, or different dragging or sweeping motion strokes, to see what works best 😁