Partner wheel: Put the kids you don't want together in the smaller circle and match them up to the kids in the larger circle! I would add arrows to the larger circle to help younger students understand their partners
Hand painted tree rings - would recommend putting all tree rings on a board (which could be painted a coordinating color to add pop to the art piece. Really neat idea for after school kids. Might just do 9 rings in a square frame!
Outlaw "I'm Done!" I LOVE this post from Kady at The Teacher Trap. She makes some really good points and includes suggestions for helping kids change their mindsets about rushing through their assignments.