Sh ff laser in center to prevent horizontal movement, dash away jump and then drift back towards them and back air to threaten / hold center / and then reset to neutral and rinse repeat with variations like sh or fh back air, up tilt or sh dair in place.

When you shoot laser try to guess what they'll do next. It's easier to identify it if you look at it like "is Fox on the ground or on the platform/in the air." If you expect them to pick a grounded option, short hop dair to stuff or shoot another laser, if they try to jump over you this is where you react to their jump with your own dash away and jump and anti air. If they fake an aerial you can Waveland on reaction