I use a rail bridge, but I let my cue stick rub against the nose of the cushion. Basically, you want to have a level stroke, but you're restricted, so just get it as level as you can. I prefer to aim at 7 o'clock, but it can be made with straight draw. Hit it as low as possible with a quick, hard stroke. Keep the grip loose throughout the stroke. I tend to concentrate on my bicep to give me the power for the stroke.