What's proper technique? Especially for alternate/tremelo picking. Should I let my picking fingers hang loosely or should I curl them in a loose fist?
Personally, I can't stand having my fingers in. It makes me feel too "stiff". My guess is that it doesn't matter. Since I see people use it both ways.
I don't think it really matters too much, but I'm like stormlexer, it doesn't feel right to me with my fingers curled up.
Your picking hand should be relaxed. If you relax your hand and look at it, thats pretty much the shape it should be when you are picking.
I find that I tense up if I keep my hand in a fist.

Though, if I am both picking with a pick and finger-picking, I keep my hand in a fist-like shape, so that they can access the strings easily.
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My hand covers more sh*t when it's open...so I usually keep it like that. Closed is nice for some stuff though too.
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Bit of both, but when my hand is open I feel more in control of my picking motion
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just do it however feels natural don't worry about being correct
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