I know this is a bit of a chestnut, but I like the paper beads you make by
using long skinny triangles of paper and rolling them around the yarn (or
whatever - string for the necklace). You start rolling at the base of the
triangle and when you get to the point you secure it with glue. They look
especially nice using magazine photos where the triangle is cut across
contrasting colors.
But there are millions of methods to make beads that 5 to 12 year olds can
master.