I hang my cup in the float box and gently set my hydrometer into it. When I'm ready to do a test I hold the hydrometer in the hand that I'm holding the cup in and work the draw off with the other. Being gentle is what it's all about. I gently lower the hydrometer into the test syrup so that the hydrometer doesn't bang off of the bottom of the cup and then open or close the draw off as needed. If the hydrometer is stuck to the test cup I fill it with hot syrup to free it up.