I spend a lot of time with students trying to get them to stop with the "death grip". Most of the time, handtools require a light touch to feel the vibration of the cutting edge as it slices and holding too tightly simply deadens sensation and causes premature fatigue.
One exception to this is during sharpening. I am on my usual crusade to relegate sharpening jigs to horse and buggy status. The image below is an example of the pressure that I exert directly over the bevel of the tool as I pull it across the stone. It isn't necessary to be able to do this without the assistance of the other hand on the tool, but it correctly describes the distribution of the pressure. The hand on the handle should supply just enough help to make up for the weight of the handle. Try it.
I remember watching experienced sharpeners use all sorts of seemingly carefree hand positions and motions during sharpening. Good for them, but it only served to cloud the issue for me. For those weaning themselves off of the jigs, I suggest starting with your thickest blade with a complete hollow grind. This will give the most feedback as to when it is truly cubbed against the stone (your stone is dead flat, right?!). Once you feel this solidly, pull the tool back across the stone. At the end of the stroke, lighten up on the pressure and the tool will naturally lay back on the heel of the bevel. Pick the tool up and put it back on the stone furthest from you, repeat. Yes, I am advocating just pulling, with the tool held slightly askew for better stability. By just pulling you can better focus on keeping the correct pressure and you are moving closer to your own center of gravity. Also, the tendency of the tool will be to lay back harmlessly on the heel of the bevel versus the disastrous tipping onto the toe, which can dig into the stone and easily send you back to the grinder.
It is more important that the tool is in the correct position than how many strokes you take. Remember, one lousy stroke will misshape the point and undo all of your good strokes. Water stones etc... cut fast enough that with a hollow grind, it won't take but a few strokes done this way to be ready for the next stone. So bring your elbows in, and push the bevel into the stone until your knuckle turns white, if it doesn't feel awkward at first, your probably not doing it right!