I guess we can start at the basics most of us probably know,bending the line tie up will make your plug swim deeper and vice versa this should be done in small increments too much bending may cause your plug to roll over.

If you have a plug that is rolling it is not the worst thing in the world try removing your tail hook and replacing it with a spinner blade the flap tails work the best IMO(Giving a little pop every once in awhile with a swimmer can be very helpful)

Fishing ML around rock piles I like them to run deeper (pikies,slopehead dannies) if you do hit a rock stop your retrieve this will give the plug a chance to float up and not snag up on the rocks and when you start your retrieve again be prepared it often appears to be a baitfish seeking safety in the rocks.I also like to have those plugs painted as a blackfish,porgy or bergall.

I like to try and tune mine to have a slight roll and still have a decent tail wiggle.When you test them it is better to be in a higher place so you can observe exactly what the plug is doing the one thing you do not want is the plug to roll over completely and cause you to lose contact with the plug.

In the case of the plug rolling too much bending your line tie up slightly should correct this and naturally if you want more roll bend it down some.

When a ML is properly tuned it should have a side to side wigggle with some roll and a wagging tail so as to have the paddle tail or spinner blade move side to side.

Another little trick is if the ML is swimming to far right bend the line tie to the left some and vice versa sometimes when your wiring the plug the line tie gets off center.

Tail hooks are fine but most of the time the bass will hit the front of the plug anyways.This all seems complicated but once you get the hang of it you will have greater success with ML plugs.

one fish could also knock the tuning out again also just pay attention to what the plug is doing after awhile you will get a feel for what the right swimming action feels like.These can be deadly on big bass they often like to follow it and take it at the last moment so don't lift the plug out of the water.