That's an excellent point, and you've given me some insight into what we should do. Perhaps a couple of hours of filming general shots to yield 15 mins of general footage is a good idea...
Some general rules of thumb:
1. Make sure you understand what matched looks are and that you REALLY understand what "the line" is in a scene.
2. Don't try complicated staging if it's your first film. If nothing else, watch Citizen Kane, and copy the setups, as they're uniformly amazing.
3. Avoid shots with characters in profile. Seeing people from the side is the least interesting and least intimate. Always get them facing somewhat into the camera.
4. NEVER shoot only a single setup of anything. ALWAYS shoot some coverage from a different angle, setup, and size, so you have something to cut away to if you need to clip different takes together or lose part of the action.
5. Always shoot an entrance and and exit (thanks, David Mamet). This means characters entering and exiting the shot. It's essentially free, and can save your butt if you need cut something out and need a character to enter at a different time than in the master.
6. Shoot B-Roll of characters doing their jobs, looking up and towards other characters off camera, reacting to things they hear, etc.