On tethers.
I have a hard point right beside the companionway that I clip to normally. From there I can go below, stretch out on the settee, go to the mast to work sail or reef, or anywhere in the cockpit, but the way my bimini and life lines are set up, can't go over board on the side , and can't go off the stern. So when offshore I can cook, do chart work, take a nap, hoist, drop or reef the main, whatever, without ever unclipping.
You can see it in this picture. It's a 3/8 inch trailering bow eye, back with a stainless steel backing. The bulkhead right there is 3/8 inch thick
I rig a jack line (a flat webbing is best- doesn't roll underfoot) from just outside the cockpit coaming, up to the bow cleat. clip to that on the high side while still in the cockpit.
I think falling off the boat would tend to ruin your whole day while single hand