He doesn't have many combos, but I think you can do bite/down-throw to dash attack at low percents, as well as late-hit nair to b-air/f-air at low-mid percents.
Throw-out bite a lot because it beats shields and airdodges and is great at the ledge. B-reversing the bite from the air to change momentum and eat unsuspecting opponents is really useful too.
Try to land waft by baiting an airdodge to the ground with an empty hop, or use it near the ledge when you're bike's there to lengthen the duration of the waft.
Best kill moves are f-tilt, bair, forward-throw at the ledge, and up-smash out of shield.
Check out this wario bike guide-
https://www.youtube.com/watch?v=faMvl0XYXAc
Reflex and Wafty are really good warios.
https://www.youtube.com/watch?v=npzmEybSQ70
https://www.youtube.com/watch?v=MO5k_41V0-E