How to fix annoying habit of watch sliding toward the exterior of my wrist

This happens to all my watches regardless of whether on a bracelet or leather and sometimes even silicone. I’ve adjusted my bracelets so I have less links at six o’clock and the clasp is centered. And I ratchet my leather bands fairly tight. But for some reason, almost without fail, my watch cases gravitate toward the exterior of my wrist intermittently throughout the day. Do you know why?