STEP THREE. Your arms provide the power for the stroke, so one arm should follow the other through the water and over the top. Try putting your hand into the water in front of your head and stretch it forwards as far as it will go, slicing it into the water with your thumb first-the less splash the better.TEP THREE. Your arms provide the power for the stroke, so one arm should follow the other through the water and over the top. Try putting your hand into the water in front of your head and stretch it forwards as far as it will go, slicing it into the water with your thumb first-the less splash the better.