Maybe its the consistency of yr icing, is it too soft? Is it warm in the area that yr working?
press a little harder onto the cupcake with the frosting. Sort of difficult to understand, but maybe the frosting wasn't firmly pressed enough against the cupcake.
Cut you styrofoam in 1/2 before putting it in the bucket. You'll get less of an angle so you're not fighting gravity and you get two bouquets per styro ball.