Here are a few tips to keep in mind when directing your short film:
1. Use a monitor. Why? All the better to see you with my dear....
2. Listen to the sound to check it's sounding good
3. Think about transitions between scenes and how you will edit while filming
4. Don't forget the actors and their performance. Sometimes it's hard to concentrate on them with everything else that's going on.
5. Don't be afraid to keep going and keep pushing for every scene until you have it looking the way you want it.