There are several venues that need volunteers for float preparation and we did that in 2015 and had a riot. The closer to Jan 1st you volunteer, the farther along the floats are but its still great fun working on them a week out. There are signups available online and they probably would not turn you away if you showed up without getting a volunteer spot. We cut pedals off flowers for a while and then ground the flowers into dust and painted the Gold Goal posts on the Stanford float. Its very cool to see the floats up close and working on them brings a different feeling when you see them in the parade. Great time and fun volunteer effort.