The best way to do a no hander is with no pinching at all.. looks the best.
Learn them by learning to take one hand off at a time, then gradually take them further off and then do two hands off at the same time. I think that it's best to use a nice big jump that you're very comfortable on, to give you more time. When I say big I mean lippy.. not a big speed jump- learning tricks on those is asking for pain..
Just take your time, and you'll find yourself pinching anyway if you need to. You might believe that the bars will fall when you let go, but if this is happening then you're putting pressure on them before you let go and you need to try maybe lifting them as you let go.