Does this work?
Uh.... I'm not sure if this helps but... I thought of a strategy to approach with Jigglypuff.
I'm not sure if this works (I didn't test it on a human player yet) but what I did was I jump in the air as I approach to the opponent then I air dodge as I come closer to the opponent. Not too early. Then as I land in front of the opponent I should be holding the shield button in case if they attack. Now you have 3 attack choices:
-If they decide to shield, then I grab them.
-If they sidestep, then you use pound.
-If they attack you, wait for their attack to finish then use any attack (a quick attack) or a grab.
or for defence you may:
-continue shielding (best not to hold too long)
-side step ( in case if your opponent tries to do another grab)
-roll left or right
This is a game of choosing which one will work and guessing what your opponent might do. I'm sure there may be more choices than what I listed here.
If this is too confusing don't worry. I will try to upload a video showing this.
I hope I helped. If this doesn't work... well at least I tried to help.
oops sorry for my grammar.:embarrass