I'm a 4.0 USTA dubs player. When I stroke forehands or serves for example, I try to hit hard without reference to the ball's flight clearance over the net. I think it is too much focus on hitting hard and being satisfied that the ball is in (depth and direction aside). I think it was Vic Braden that would have people hit through actual windows above the net. Does anyone focus on height over the net and if so, how does one train/practice both mentally and physically without aids.