Maybe that's the best topic for my issue. All in all I play the guitar for more than 20 years now and since all that time I always had some trouble with holding the pick.
Justin always emphasizes that it's important to have a light grip on the pick, if you want to do pickings, especially faster ones. For me, whenever I don't grip the pick pretty tightly it has a tendency to turn with the sharp side towards the head of the guitar. This becomes quite an issue during live gigs, since I generally sweat quite alot. So I have to grip the pick even harder to keep it in position, which results in a cramping, unrelaxed right arm, especially during fast parts and songs using alternate picking (got the feeling that the problem is mainly the upstroak).
There could probably be a relation to another thing: The way to hold the pick that feels most "natural" to me is with the sharp edge pointing slightly towards the head of the guitar. If my index finger, pointing straight at the strings, is 6 o'clock, the pick is probably rather 7 o' clock. Don't know if that's generally a problem and maybe I have to change that habit?
I already use picks with a rough surface.
Any hints would be greatly appreciated!
Here's a picture of the way I usually hold the pick:
