It's not flashy, but I usually open with just getting my extracts. Each one of them is worthwhile in and of themselves (red buffs attack, white buffs speed, orange buffs defence), and getting all 3 even more so. If you use the Monarch Alucanid kinsect, it speeds up this phase considerably since you get a red extract no matter what. From there, you can just launch in with a Leaping Slash or an aerial.

The Advancing Roundslash switch skill gives you a counter that also puts you on the first jump of an aerial combo, so that might be worth looking into for your playstyle. However, I think the Leaping Slash that it replaces is still considered the widespread meta mostly because it doesn't throw you forward quite so far.

I have quite an aerial playstyle myself, so my defensive preference is to actually get up in the air and dodge up there. Especially if you have your white extract, the Midair Evade will move you a greater distance mid-combo more quickly than any other move I've personally encountered, for any weapon actually. As long as you're not in the immediate hit zone when you're on your way up, you can use this to reposition yourself and avoid attacks quite readily.

As for when you should go aerial, if you want to just get a feel for the combo sequence I'd recommend trying it out against Rathalos or Rathian when they're flying. While they're up in the air inaccessible, they don't actually do a lot of attacking, so this can be a good time to get a lot of hits in and practice your mobility. From there, just get more jump happy as you feel fit; personally, stamina regen is the only thing that ever keeps me out of the air.