I do a combination of both, especially if I'm having a rough time getting it right. I aim for only hitting the strings I want, but i'll also lift pressure off of my index finger in the area where i want the strings muted. Both things take time to get good at. Eventually, we noobies will get it down :)


I'll just add in that what I like about doing this is that let's say you're lifting pressure and only muting one string... well, that's one less string you can accidentally hit.