Main thing is to not look for that nonexistent front sight. Even a little of the slide in your "sight picture" will cause you to shoot high. Solutions include using the rear of the slide as your "sight" and, as suggested by Barnetmill, canting the gun slightly and using the top edge of either side of the slide as kind of a sighting rib.

Pushing the edge of the envelope is fun.
Most practice, though, should be fast and close, including contact shots on appropriate media.