One method of sculling while holding oneself upright in the water is to weave the hands vigorously back and forth in front of and to the sides of the body in a figure-eight movement. This forces the water downward and keeps the body up.
Another method is to drop the hands down near the hips in the water then turn the hands to about a 45-degree angle away from the body, thumbs downward. With the palms of the hands push the water away from the body. Immediately rotate the hands so that the thumbs are up. The hands now recover, pulling water toward the side of the body. When the hands reach the side they are again rotated until the thumbs are down, and the movements are repeated. The emphasis is on the push-away part of the stroke.
A third method is to place the hand palms on the water, press down on the water several feet depth, and recover again. All these methods, or combinations of them, will be useful at different times.