Well, it's not 100% reliable. Beyond just practicing till my hand is permanently into a painful cramping claw, I don't know of any secret.
One thing that helps a little when I'm not on photoshop is to use the eraser end; it seems a little less sensitive :shrug:. All my teachers tried to teach me how to hold a pencil the "Right Way®" without success. Maybe there's an upside to the way I hold my pencil. Or maybe it's the effect of having my knuckles rapped with a ruler for years on end... Catholic school rocks... and stuff :x. I know the way I hold a pen certainly wakes up the carp in my tunnels. :oHm? That sounds a little dirty...:P
Oh! Try reducing tip sensitivity in the Pen Tablet control panel. I don't know the Windows(©Microsoft, Inc.®) way of doing that, but there would have to be some equivalent driver preferences or settings panel.:?:. Might help.
I think I understand the problem: you thunk the tip down and it skitters across the surface a little. The only solution I know is practice. I've found the softer my touch gets, the less I have the problem. This is my observation from less than two weeks of constant use.
I think the issue is that when I press down with the tip it registers as a "click-drag" with the OS rather than just a click.
For example, I find it very hard to select a node in Inkscape without moving that node (as if I had click-dragged).
It could be related to the way I hold the stylus/wrist mechanics. Do you hold your pen angled or vertical?
I hold it different ways depending on what I'm doing. I think when I "click" the tip I do tend to move it into a more vertical position though. I'll have to pay attention to it when I use it next to see. I will say that yesterday I sat my son down at it and had him play around in PhotoShop to see how he took to the tablet as well as the application. He had no problems with the stylus right out of the gate except for two things. The first was that he kept trying to use it like a mouse and picking up and dragging it, and second was he kept hitting the stylus button. Once I showed him how the tablet mapped to the screen and that the stylus would "jump" the cursor he was zooming right along. He didn't have any clicking issues either as he moved from one tool to the next and selected layers and such.