I tell my kids that d's wear diapers. They think it is so funny and they remember where to put the circle part!
Hand signals for the kids during guided reading. It would teach them a procedure and avoid the distractions during silent reading. You could use this for grades 5th and down and it would help you meet Teaching Standard IV Learning Environment, Element IV.3: teachers manage the learning environment for the effective operation of the classroom.
DIY Vision Tracking Tube using colored electrical tape, bouncy ball, and "clear polycarbonate tube lamp guard" from Lowe's.
Visual schedule with pull down flaps + magnets. When item is completed, close the flap, and the word "done" is on the outside.
Good way to teach how to differentiate between "b" and "d" Very Clever!
Visual cues for following directions