right now I'm learning how to wave dash. I'm getting use to the gamecube controller and short hopping is a little different from the 3ds.
Best thing I can say is to slow down and build up to perfect wave dashes. Jump -> air dodge at ground. Slowly build up until you get the hang of jumping and almost immediately air dodging. This will be used a lot for Lucas as he has a great wavedash. Magnet can be jump canceled, which means you can also wave dash out of it. Not to mention it's a great spacing tool.
I still accidentally full hop every once in a while, but overall I am consistent with my tech skill because of hours of practice & playing. I didn't start wave dashing much until about 2-3 months into playing the game, but then again I started off as an Ivy main lol. Lucas takes a lot of tech skill and you'll find it very hard to play him without short hopping. But the rewards of playing him and the joys you will feel are like none other!
Wave dashing & short hopping takes practice and a bit of patience.
Also when is it best to grab and what combos can go into it?
There's a few setups into grabs. I don't recommend grabbing in neutral, especially not to fish for a chain grab or kill throw
DJC PKF will be the most general lead into a grab. It works very well on mid weights. Almost never use on floaties- they go too high up, and on fast fallers- they can crouch cancel the hit or are back on the ground very fast.
Against opponents who shield a lot this can be a good tool. Be wary of evasive people & characters. The end lag for whiffs is atrocious
Out of grabs, Fthrow around 0-20 can get a regrab bc it doesn't send you into tumble and it may throw off the opponent. Typically Dthrow is the best on everyone. Uthrow chain grabs fast fallers & sets up combos until 80-100%
Out of down throw there are so many options to choose from, it all depends on enemy's DI and % Dthrow -> Bair / Upsmash is a bread n butter kill setup with no DI, substitute for Sweetspot Fair / DACUS if they DI behind you. Some other basic BnB combos are Dthrow -> Utilt at lower % and Uair / Fair depending on their DI at most %. This leads into more combo hit strings upon hit confirm. After that, just follow their DI.
I'm writing up more in the combo section of my guide at a later point. Currently I have combos on Fast Fallers.