Kickboard Kick or Kick on Back with hands over head, fingers locked.
'Pull' Drill - Focus will be on learning to 'catch' the water with your forearm and pull yourself through the water. If you feel your lats (the muscles under your arm pits that go down the side of your back) engage, then you are starting to get it. If your shoulders are tired, then you are still using too much shoulder and not enough lats.
'Pretty' Running - Lean forward, roll off your big toes, keep hand above your waist, look about 6 feet in front of you with your eyes, drive your elbows back and never cross your midline with your hands.
Stretch in between sets as well.