This was a disaster! I have done something similar with marbles to create a lovely firework picture, so I thought I would try with polystyrene eggs. Unfortunately they were too light and kept sticking. I would do this again, but use hard boiled eggs. This would then work a treat!
Put paper in the bottom of a tray, and roll paint covered eggs over to create a pattern. There was a small picture of the Easter story in the middle of the picture.