In 2013 on team 308 we realized that we needed a way to block shots from the corner so we used "locally sourced materials" left over from lunch (otherwise known as a pizza box) and a bit of duct tape and that worked ok. Later in the season we replaced it with a fiberglass driveway marker "borrowed" from the parking lot of the event and that stayed the rest of the season due to how well it worked.
Pizza Box Frisbee Blocker