To make threading the beads onto the cord easier, use a needle with a large enough eye to accommodate the stretch cord. Make sure that the needle can also pass through the beads.
Thread a stop bead (a spare bead that is not part of the design) and tie a knot to secure. This will keep you beads in place as you work.
Pattern as follows: *3 hole spacer bead, 20 beads, 3 hole spacer bead, 20 beads, 3 hole spacer bead, 20 beads, 3 hole spacer and finally the last 20 beads on this row*.
Pass needle through the first 3 hole spacer bead, making a circle.
Loop the stretch cord down into the next hole in the spacer bead and repeat above * * for the next two rows.
Loop the stretch cord up through to the knot on the first row and secure tightly with a couple of knots.
Remove the stop bead and snip loose ends.