From watching many of the CTC videos, it’s clear that Troy has mastered most if not all of the various primary motion techniques discussed here (elbow, forearm, wrist, combinations of the above, etc.). My question for Troy, or for anyone else who has progressed through multiple techniques, is were you able to tremolo pick all of them from the start, or did you have to work up to that? The reason for my question is that the only way that I can currently tremolo pick is from the elbow, but after spending a few months on that, I can’t seem to gain any consistency or make any progress, so I’d like to explore some of the other primary motions discussed here. But I’m wondering if that would be a waste of time, seeing that, at least at the moment, I can’t tremolo pick with any of the other primary motions except for the elbow. So for those of you who have mastered multiple techniques, were you able to tremolo pick all of them from the get go, or did you increase your speed on the ‘new’ primary motion over time?
I am also curious about this. I’m a dsx user, and I’m practicing and reinforcing dsx movements, but the player I admire is Eric Johnson, so I have a dream about usx, and actually, my usx is not as fast as dsx, but it’s speed is also fine and i feel it natural to play. So I want to master dsx and move on to usx or practice dbx! While thinking about this, I also wondered if I could have various motions…
I think I can do multiple motions but definitely pros / cons for each. I’d say they all built up over time roughly the same pace. Once you feel really good about one, knowing how the others should more or less feel makes more sense.
Very good question! Have been tryin different ways to tremolo pick, recently i discovered elbow and i consider it to be the easiest way to play, i guess it may be due to the fact that you can use the weight of your whole arm to do the picking, so it’s easy to create a pendulum. For a long time i’ve had doubt about elbow playing(recently my current guitar teacher from my music school has told me, that playing from elbow is fundamentally wrong), a while ago i learned how to do elbow tremolo at 140-150. It wasn’t like an instant upgrade to fast tempo, rather gradually getting more and more comfortable. Couldn’t do the string changes first, so i didn’t know, if it’s gonna work, but now it seems to get more and more constistent and i can play some 1nps as wel as scalar lines(i don’t really know what secondary motion i use, probably some wrist). Gonna post some footage soon, when i find someone to film me playin 
maybe it will be useful. Also my answer seems not to fit into the context of your question as i really only can do one primary motion, but whatever 
My first tremolo was a pronated wrist DSX. I don’t really remember if it worked right away but I don’t recall having made any progresses in speed. I guess the speed was there from the start.
After finding CtC I decided to work on a supinated rotational USX in the vein of Yngwie and the motion and speed was there more or less right away. The speed was actually far higher than the wrist and I could even do the motion in the air without the guitar. The work have been to get stability and reliability in the motion when applying it to the guitar. It took some weeks to get that to work if I recall correctly.
Interesting to know might be that I can’t get elbow to work at all. It just feels like a mors tense and stiff version of the wrist motion.
@jay2377 Do you mean able to tremolo pick at top speed? Definitely worked up to it for some cases. It’s pretty much the same as anything I practice - if I’m being handed the correct movement already, I just alternate between practicing it slow and trying to see how fast I can push it. I also have recently been going back and purposely working on reducing tension in my playing, usually by playing things I know I have down mechanically at whatever speed I can get to without tensing up and making sure the mechanic is consistent and I don’t have some bad habit that crept in that’s causing the tension, then trying to push up the speed from there. Sometimes I’ll go way over the target speed and come back down as well, knowing that it would cause tension but allow me to relax when reducing speed back into the target speed.
Personally - I like to practice different motions by learning a difficult piece by a player I like who has that motion and use it for that. I think a lot of the time when a really good player has trouble mimicking other players - it’s because their primary motions are incompatible with the licks of the other player, so if they learned the other primary motions, it might be natural to learn their licks.
This is probably a misperception. I only was able to forearm type motions at first, although serveral slightly different versions of it, some with more wrist than others, Doug Aldrich-style. It took years to learn how to do any kind of wrist-only motion. And I still don’t do DSX elbow, or anything with fingers.
If you want to experiment, that’s totally fine. It can be a hobby of sorts, like people who learn martial arts but aren’t interested in competitive fighting or self defense. But if your goal is making music quickly, that’s the reason we usually tell people to go with what is working. It can take years to figure out how other motions work.
FYI on the rare occasion I try to play lefty, I can only do wrist. I don’t have to tell the forearm to stop moving — it doesn’t know how, so it is motionless. This is a useful way to remind myself what it’s like for players who only know that way of moving. And despite the years it took with my other hand, this apparently has always been that way, I just never knew.