Get large beads with wide holes (wood or safe plastic) and a thick string or shoelace with a knot or a bit of tape at the tip to make threading easier. Have your child hold the string in one hand and a bead in the other, then carefully pass the string's tip through the bead's hole.
Start with large beads and wide holes for younger children, and gradually shrink the size as their precision improves. Add an extra layer by asking them to thread beads in a specific color pattern (red, blue, red, blue) to also practice sequencing and sorting.
This activity significantly strengthens hand-eye coordination and fine motor control, improves focus and patience, and is an excellent lead-up to later skills like handwriting, tying laces, and doing up buttons.