I usually have a problem online trying to shield a hit I know/see is coming, and usually when I shield, I still end up getting hit or when I wanna drop my shield to try counter attack or something, I can't do it on time (cause of lag I guess).

So how do I shield drop and is it better to use online than regular shielding?

Hope this makes sense lol.

Have a Walk/Dash button
Shield > hold down Walk/Dash button > press down

Seems to me you don't know what shield dropping actually is.

What is Shield Drop? Shield dropping is dropping through a platform, while you're in shield. Note: This isn't you dropping to the next platform or floor with shield on you. It's simply you just dropping through that current platform. It can't be done on the main stage, since there's no where to really go.

What isn't Shield Drop?: It's not really a defensive move, but a way to escape or to move along for repositioning. Hence why it's not going to help you shield better, nor is it going to protect you. It's just a way to get away. It CAN be used defensively if you're above the other player and shield then shield drop into an Aerial. But you might want to be quick if you want to do those right.

How to preform a shield drop?: Go on top of any platform. (Hold Shield > then hold the walk/run button> then press down.)
Make sure you press down last one you'll end up spot dodging.

I'll nitpick here: shield dropping is usually defensively motivated. Releasing shield takes a couple frames, and so does jumping. Shield-drops allow you to attack out of shield much faster than normal: look at aMSa in Melee for a great example of this technique used defensively, although it's more effective there because Yoshi can't jump OoS in Melee and has a tether grab. Characters like MK have shield-drop uair, which is really, really, really, REALLY, fast, and can nab characters like Fox or Falco that aren't used to counter-attacking options during their shield pressure.

Thanks for the replies guys . i'm trying it out and so far it's been pretty useful.