Movement tends to come naturally as you get better, but it's definitely something you should continually practice on your own. Most good movement I'm impressed by isn't particularly flashy as much as it's efficiently getting to a certain position. If you watch Hax play a lot of his movement in neutral is using wavedashes of every length and shield stops to get very fine spacing. As your situational awareness increases you'll start to understand where you need to be in order to cover options or punish your opponent best.
Some things to practice that are:
Shield Stops
Different length wavedashes
Wavedash down
Dashing after an attack
Dash dance length/spacing
Walking in general
Fast fall timing (or choosing not to fast fall at all)
Falling through platforms without landing on them
Crouching out of a dash (as well as immediately returning to standing position)
Getting to the ledge efficiently (Choosing the proper option to get to the ledge and performing it as quickly as possible) as well as getting off the ledge efficiently
Isai drops
Shield drops (especially immediately after you land, dash, waveland, etc.)
Pivots
Practice linking these all together with attacks placed in between. You can add flashy things like edge cancels on aerials/illusions or fancy shine turnaround waveland **** whenever you feel like it but what really separates the top foxes isn't the flashy **** that's difficult to do with little applications as much as it's doing even more with the basic techniques than lower level players do.
