One thing I've found VERY useful, well... two things:
1. Get a mouse that has a programmable button (mine is a Logitech MX Revolution). Map one of the programmable buttons to do the keystroke combination "CTRL ~" Now you are free to ALT Zoom/Pan with your mouse and then just tap the button to take the snapshot. It is great for taking many snapshot. In a photosession I will zoom and pan around my subject and just click click click click.
2. Use the "Freeze Frame" feature in the photo dialogue of your viewer. I believe you have to pull down the extra features at the bottom of the dialog to get the checkbox for freeze frame. Once you've frozen the image, use your ALT Zoom/Pan features to orbit your "frozen" scene to get the best angle. This is a feature not well advertised. This is great for trying to capture moving events or scenes. Just keep freezing the moving scene (wedding, dance, road race whatever) until you get a "scene" you like. Then once you've "frozen" it, orbit around and use CTRL 0, 8 and 9 to get the right framing and then save it to disk.