I use all of these , since I hold the pick between index and thumb , and I don't roll the other fingers ... Some people like to roll their free fingers , so they depend more on Palm and Fretting hand muting .
Any music line that changes strings a lot is gonna be a good exercise for muting ..... Set your distortion on max and play .... Whenever you find a part that doesn't sound good , or isn't muted enough , cut it down , try different techniques , play it over and over till it's perfect (or at least better) .