The grip is important. When my hand gets sweaty I can't serve at all. I've destroyed a couple of racquets when they've slipped out of my hand and caved in the head when serving with sweaty hands and an old grip. The newer grip allows you to have a looser grip on the racquet without it slipping. The looser grip keeps the wrist and forearm freer to move.
On the serve, I'd work on the basic motion with the continental grip. It's a big change. Serve for a while at a slow to medium pace and make sure you're hitting all the correct points in the motion. There should not be any quick, jerky motions before you pull the trigger and swing into the ball. It should be relaxed and natural feeling. When it's right, one sign is that you'll be hitting pretty hard with relatively little effort, and you'll end the stroke balanced and ready to recover.
Last edited by rkelley; 10-05-2013 at 09:37 PM.
Reason: should to "should not"