Pick up a Zenith Archery "No-Punch" training kit (
http://zenitharchery.com/zap_no_punch.htm)
It comes with a release (one of the best pure BT releases made), all required hardware for the release and most importantly, a video tape that shows you how to properly draw, fire and let down without ending up with a bloodied lip. At $79.95 it is a great deal, considering the average price of a target BT release these days is around $120.
In my quest for the perfect BT release....for me....I have probably tried about 12 different models and just keep coming back to the Zenith.
One other thing is that I have NEVER had a true BT release that prematurely fired during my draw or let down. Once you know how to draw and let down the thought never even crosses your mind. I have also had a number of BT releases with safteys over the years. The one thing that has been consistent with them is that I have managed to punch myself in the face with each and every one of them. Not all of the punches were release failures of one sort or another, most of them were my fault, however the saftey is just one more thing to have to think about when drawing or letting down.