Change sides one or more times per length. Flutter or dolphin kick. Kick on your back. Lie on your back with hands at your hips making small sculling actions. Intermediate swimmers extend one arm overhead.
Advanced swimmers extend both arms overhead in a tight streamlined position.
Head in a comfortable position, hips up, knees underwater, toes ruffling the surface. Keep the arms at your sides, or extend them in a super-streamlined position. When you need a breath, take a breaststroke pull and surface. Don't hold your breath past the point of discomfort. Kick with fins.