Ref. grips... if ya folks are turning with "death grips", you're not enjoying your turning NEARLY enough. Sure, you need a stiff grip if you're using the side of a fingernail grind... but if you're using the tip (or a skew, or a scraper), you can really relax your grip with both hands.
Ya know how, when you're driving on ice, it's best to use only your fingertips on the steering wheel to ensure you're not driving with the death grip that'll take you off the road? Turning's a lot like that - you can turn with both hands almost fully relaxed, and enjoy it a lot more for a longer time. I very seldom have more than fingertip grip on any turning tool's handle, and my guiding hand is only tense enough to make sure the gouge won't skate sideways on me. Except for heavy roughing, of course, when I've got my palm on top of the rougher or bowl gouge. Mostly I've got my index finger underneath, against the toolrest, and I'm guiding my gouge with the tip of that index finger and the tip of my thumb.
Like welding. If you're NOT comfortable, your work won't be as good as if ARE comfortable.