Your Basic Wave Dash:
So this will be easy! All of your Wave Dash buttons are literally lined up on the bottom row for your right hand. You Wave Dash with your middle and index fingers on "X" and "L." Then to WDOoS you simply hold "R" down with your pinky finger! Since your pinky works as an anchor, your other fingers are still unencumbered to act freely.
Now to Wave Dash out of Light Shield, we simply add the "L/R mod" button (a.k.a. "Shield Mod") down with our ring finger. So all of your fingers will be doing work!
Holding down the shield modifier, it turns your hard shield into the lightest possible light shield. The only thing you need to know that's tricky is that you NEED to let go of the Shield Mod. Your shield will be so light that your L won't produce a wave dash! So you need to be quick and let go before your jumpsquat frames end.
And there you have it! All of the buttons are lined up in a row to make it as easy as possible to WDOoS in a match. No more squeezing long and lanky triggers. Rejoice!