• Use 3rd person.  (e.g. "The team discovered…" not "We discovered")
• Change expletives such as  there are/it is/that was into active.  (e.g. "Three days remain…" not "There are three days remaining…")
• Use active verbs instead of passive. (e.g. "The team voted to…" not "The vote was passed to…")
• Use active verbs instead of "to be" verbs. ("The group agreed often" not "The group was often agreeable")
• Edit out unnecessary repetition and wordiness. ("The group avoided conflict" not "Conflict within the group was not really an issue when it came to this project")

Get it in writing: What style problems did you have in your group's project proposal that you'll avoid in your project report?