I cover all that in this tutorial on building speed with a focus on tremolo picking.
https://www.guitartricks.com/tutorial/287/
You've got the right idea with grazing the string. Going too deep into the string inhibits speed. Essentially, use minimal motion & stay relaxed. Wide motions & tension inhibit speed. Hope that helps!
Hi Christopher,
Thanks for pointing me toward the tremolo tutorial. I've started working on it and am slowly getting the hang of it but still inconsistent when I try playing 16th notes at 120 bpm along to the backing track. I think it's a combination of factors that will require some more practice. The play along videos and the ability to loop and modify the speed are fantastic practice tools!
I notice that as I move on to the A-minor lick along the high e-string that you're not using your pinky finger at all. Is that personal preference? I feel like I should be using my pinky whenever it's reasonable, so that when I "need" to use it, it will be better coordinated.
I appreciate any additional guidance.