okay, okay, im not gonna be harsh buuuuut...
Do's
1. SHL (if you main falco its not a problem)
2. SHDL (a litte bit harder at first =p)
3. shffling (you should be able to shffl with any character, its not just a falco thing)
4. dash dance (not just a falco thing)
5. JC grabs (you need it with fox)
6. learn to waveshine (you cant waveshine luigi into anything but it helps with mobility)
7. check out dalal's fox movement tricks (theres useful stuff in there for other characters too)
8. if you come seeking advice, no johnz (clueless was right about your tech skill being subpar, so just accept some helpful flames until you get a little better)
Don'ts
1. Dont wait for the opponent to run into your charged smash attack. (the exception to this is waiting on the ledge for a predictable recovery)
2. Dont always go for the shine spike (i liked that you used some, but sometimes a back air off the ledge and into luigi's face is better)
3. Be more aggressive but use it intelligently, dont just dash attack around.
4. Dont roll so much, it really hurts you in the long run.
5. Try not to laser on the ground at all, let alone when the luigi is right next to you (luigi has a long painful wavedash to show you when you start lasering on the ground)
6. Don't think you own cause you got that 3-stock, humility is an important aspect of the game when youre attempting to better yourself.
All of the technical skills i've mentioned can be found in one of the stickied guides (i suggest reading cunning's) in the fox character section.
Keep working, thats all ive got for now.