Never give up on the snap shot, it is the most effective shot in hockey; it is quick and accurate, you will be able to execute it far more times than the wrister because of the time of release. My slapshot still sucks horribly, but I realized the snapshot is more like a slapper technique-wise than a wrister, it is essentially the slapshot without the windup, and it is my alternative to the one timer when around the net because it has the accuracy of the wrist shot. From a standstill, give the puck a little nudge to get it going and try flicking the wrists.
One thing that might help, square your body with the puck, set the blade down about 2 inches behind the puck and shoot it from that position only using forward momentum with your stick. If you aren't flicking your wrists, you aren't going to get much on the shot. The key is to not make contact with the puck before shooting it (for this drill) and keeping your stick moving towards the target. With the puck not being on your stick, you are going to be forced into flexing it on the ice to give it some oomph, it is something I think could help a lot.