First day project: Friend Tree. Everyone puts their thumb print on the tree then teacher later frames it and hangs it as a reminder that we are all friends. I could even use it at open house and let the parents join us since we're all a team.
What a smart way to use your first day of school! Have each kiddo make something with Playdough while you are taking care of the housekeeping (supplies, attendance, mini-conferences, etc.) Then have students write about what they made. Your kids are focused, and you end up with a beginning of the year writing sample!