I think the stick grip as supplied by ICP is actually a pretty good shape (unless you're wanting more buttons): specifically because on a full flaps approach you are out of trim and holding the nose up (also a good arrangement, allows the nose to be dropped promptly if airspeed decays).
It has scalloped finger grips at the front, and a more pronounced protrusion at the top front.
But it is made of some solid rubbery stuff, a bit sticky in summer, I have been flying it with a handkerchief wrapped round it. This thread finally prompted me to do something about it:
There being a shortage of kangaroos over here, I bought a leather steering wheel cover, cut a section out of that and laced it on. So far I've done one side (it's a Y stick) and I'll fly that for a bit to check that it's tight enough, then do the other side.
Okay, it still doesn't look like a Ray Allen creation, but I'm pretty pleased with the result. Expenditure so far $20 and a couple of hours measuring and sorting out tidy lacing, the other side will go much faster.