Paper Piercing ?
 

I have the stampin' up paper piercing mat pack tool, but my problem is that my lines always come out unevenly. Even though I am using the tool I guess the paper shifts. Does anyone have any suggestions on how I can avoid having this happen?

I use my left hand to hold the cardstock and template firmly in place while piercing with my right hand. It also helps to be on a flat surface such as a table.

I get this sometimes too. One thing I might suggest is to try and use needles that are closer in size to the holes. Don't use a really thin needle in the bigger holes, I mean. If that's not it, maybe see if you can check yours against another's? It's possible that the mat is just "off" a bit, too.

Try using repositionable tape to hold down your project. This should keep it from shifting.

Try using a bit of Dotto removable tape on the template to hold it in place. It seems to do the trick.

I've been using plastic canvas and the holes are quite a bit bigger than the needle (which isn't small). My question is......are the holes in the SU tool smaller so I'm more even?