Shwagzamaxima
Smash Cadet
For lightshielding, I don't really know what to recommend, as I find it useless playing Mario/Falco/Fox and now Metaknight in PM.Well, I play G&W, so I need to learn to lightshield on command. I can't yet, but I'm getting there. The problem comes with jab>grab. I can jab fine, but I'll often try to grab too early with Z, so I mess it up. I need to get the timing down.
For jab+grab, practice them separately. Go on FD, like I told you before, with a CPU (very important, don't just do this with an idle human) and run, jab, turn, run, turn around, and repeat. Just jab and run, over and over, until you have the length of the jab animation hard-wired. Then grabbing out of it will be easy. This is what I did with jabs and tilts and stuff, as I was getting too dependant on aerials and shines.