I check multiple times prior to landing. Gear gets selected down prior to any descent to land and my finger stays on the handle until 3 greens & the extension cycle is complete. I check on downwind, base, after turning final, x-ing the FAF, the OM, 1000', 500', approaching DA/MDA & lastly just prior to closing the throttle to land. Not all of those points happen during every landing eg VFR circuit pattern vs ILS, but at least 3 or 4 of them do.