Now that you are all filming your trailers I would advise you to refresh yourself with the "How to film links" particulary this one
Other tips.
1-Stick to your storyboard and make sure that your trailer does not look like it was filmed in one afternoon in school!
2-Each person in your group has a role and they must do their job. Props/Clothes/Location are particulary important at this stage.
3-Use the shooting schedule.
4-Do not take the tape home!
Good Luck.
