Like Nike says, just do it.
A $10 hobby wood burning kit and a cold beer is all you need. There are plenty of really nice looking stippling jobs, but even the basic pointillism style is super effective. Key areas are under the trigger guard, front strap, backstrap and beaver tail. Even on these I did sparingly, just where my hand makes contact and just where I felt there could be improvement – an example is the vertical lines on the Glock backstrap.
The common complaint is that folks are afraid to “mess it up.” There’s enough polymer odds and ends (A2 grips, magpul widgets) that you can practice with. Even when it comes time to do the deed, you just make sure you don’t lay the soldering iron on the gun and you’ll be fine. You will not poke a hole in the frame – well you could, but you would have to try. If the stippling is too aggressive, take an emery board or some sandpaper and dress it down a little.
You want to try before you fly? Pick up some grip tape at your local hardware store and give it a spin.
One word of caution is the “over stippling” you see on many guns. Just like sharp sights wear holes in jackets and shirts, stippling grips will do the same. You can’t unstipple easily – start small and work big, there’s a point of diminishing returns.