Once all of the extra grip tape has been cut off, you may want to rub down the edges more with the screwdriver, depending on how well you did it before. Keep trimming these edges until you like them.
Another option that I've used is to next take your deck out to a curb, and rub the edges on the concrete. This will sand down any badly cut grip tape edges, and make the transition from grip tape to skate deck smoother.
