Anyone have any tips on how to make a flat serve more consistent? I usually use a slice or topspin twist serve. But every once in a while I like to drop in a flat serve just to surprise my opponent. Problem is, either my flat serve hits the tape or goes about 10 ft long. Any tips on getting it to go in? Note: I am not talking about hitting a flat serve as hard as possible, I am talking about hitting a fairly solid flat serve at about 60%-70% effort.