Gather your strings in groups of two and fold them in half. Loop each folded group around the hoop. Place the folded end under the hoop and pull the ends over the hoop and through the loop created by the folded end. Repeat with the other two groups and space them equally apart around the hoop, about 10-1/2 inches apart.
To create a square knot lay your four strands from one of your groupings flat on a table. Take the outside string on the left-hand side and place it over the other strands. Take the outside string on the right side and place it over the string coming across, then under the two center strands, then through the far-left loop. Pull tight and repeat these steps starting on the right. Place the far-right string over the other strands. Take the far-left string and place it over the crossed strand, under the center strands and through the loop on the left. Pull tight and you have completed one square knot.
Three inches away from the top of your square knots you will start the spiral. To create a pretty spiral effect, you simply repeat the first half of the square knot. Lay your strands flat. Place the outside left strand over the remaining strands. Place the outside right strand over the string across, under the center strings, and through the left loop. Pull tight. Repeat, always starting with the outside left string. (Instead of alternating which side you start the knot, start on the same side and the macrame will twist.) Continue the half knots until your spiral measures 1-1/2 inches. Repeat on the other two groupings.
To create interest, divide the strands into new groupings. Lay the hoop flat and lay the strands of two groups of strings that are next to each other flat on the table. From the left-hand grouping take the two strands on the right and from the right-hand grouping take the two strands on the left to create a new group of four. Three inches from the top of the spirals join this new group with two full squares knots. Repeat these steps with the other strands.
Six inches from the last knots, join all the strands with the half knot. Choose two long outside strands. Place the outside left strand over all the other strands. Place the outside right strand over the strand coming across, then under center strands, and through the loop in the left. Pull tight and repeat until you have a spiral measuring two inches.
Add the final square knots to create a loop for hanging. Six inches above your large spiral, complete three square knots, move up an inch and then create two more square knots. Trim the stings and your mobile is ready to hang. Use the gap between the groups of square knots to hang your mobile from a hook.