When you are afraid that you might not get the sticker just right on the page, you can remove it from the paper it comes on, and place half of it sticky side down onto a hard surface, like cutting board, lift it off and do the other half. Repeat a number of times until it becomes re-positionable on paper.

OR:

Another thing you can do is place the sticker onto clear vellum, cut it out, and then glue the sticker onto your page.