This may get closed because it belongs in some kind of technique forum or thread, but considering it relates specifically to hardcore I figured I'd get a better answer on here. I don't play much hardcore at all (when I do its mostly misery signals typed stuff), but I occasional have a jam with some friends that play hardcore, and I was wondering in breakdowns etc. Which strings you picked, whether you just pick the E string, or you pick both the E and the A string (obviously C or just C and G if you're tuned to drop C, B and F# if you're to Drop B etc.) Yeah I was just wondering, because I like to pick both the E and A most of the time, but some of the guys I jam with just play the E-string. If this doesn't make sense, let me know, i'll give some tab examples.
It depends on the breakdown. The more brutal breakdowns come with the doubling of the strings, the less brutal ones come with only one string.