Nice... Clutch is great. Anywho, it really depends on what kind of picking style you feel you have the greatest control over and the fastest speed with. It definitely sounds like a tremolo-picking riff, and for me, I do them one of two ways depending on how many strings I'm trying to pick. Typically, if it's a single string, I do wrist picking where I'm moving my wrist rapidly to pick the one string, but if it's multiple, I typically lock my wrist and essentially pick by moving my elbow rapidly. There's no one right way to do it though; just start trying to do it reliably and increase the speed as you continue to practice.
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