Shots from a tight angle always seem to be a goalies problem. You don't know if you should be in your regular stance or a narrow stance, butterfly or stand up, challenge the shooter or stay on your post.
There are a couple of things that you should always do when there is a shot from a bad angle. Make sure that you come out and challenge the shooter. If he comes in close then you can start backing up. Play nice and aggressive. Keep your stance a little bit more narrower so that you are square with the shooter and your feet are in line with the posts. If you use your butterfly, make sure that it is narrow and just in line with the posts so that when the shot is taken, you don't let out a big rebound out in front of the net.