I'm gonna go ahead and say a [words=http://www.mattersofsize.com/forum/showthread.php?83577-Length-master-official-order-thread-now-shipping-06-16-2014!!!]
length master[/words] would make that a pretty easy problem to solve.
Try using a towel. I use an automotive towel I got at a pharmacy. Low friction and high [words=https://shop.mattersofsize.com/products/sizegenetics-penis-extender]traction[/words].
Otherwise you can try creative grips. Sometimes I mess around with erect fulcrums at the base. I grip the shaft just above where I want the fulcrum and push the base down. I lift the grip and try to push the fulcrum out. Definitely feels like an expressive stretch, I just worry about creating an upward curve, but I suppose that's probably countered by doing a fulcrum the opposite way.