Fast falling before the aerial sometimes cancels the aerial before it even comes out. And since you can't fastfall during an aerial, most aerials are just done with a short hop, and that's it.
Short hop, attack, fastfall, lag-cancel
Not possible.
Short hop, fastfall, attack, lag-cancel
Possible, but applications are limited to characters with fast enough aerials, or high enough short hops (like Luigi). Easiest with dair (since you can input it and the fastfall at almost the same time). Unless your fingers are so fast and precise they can flawlessly switch from the fastfall input to the aerial input in a couple frames so it almost looks like a Melee SHFFL.
Short hop, attack, lag-cancel
Probably the most common.
Slanted full hop, fastfall, attack, lag-cancel
This kind of fastfalled aerial approach is a bit more common than the short hop version.
Edit:
Short hop, attack, attack, lag-cancel
Lol. The Mario brothers can do this because their uairs have the shortest start-up lag of any aerial in the game.