I seem to get the best results by double tapping for the first dash, then pressing forward and moving to u/f, then releasing immediately. Tekkaman can get across the entire screen very quickly, which should make him that much more deadly.
I imagine this would be very useful against a character like Cabl–Saki. She super jumps and you can zip past her nonsense from below, patiently waiting for her as she falls. :lol: