1. tie a clove hitch round the first pole/upright and tuck the end in neatly.
2. pull the clove hitch very tightly, and take the long end over the second pole/crossbar, round the back of the upright and over the crossbar again.
3. follow the same course, being careful to lay each cord alongside the one before and to pull tight all the time, until you have reacher each part three times.
4. take two or three frapping turns behind the crossbar and in front of the upright.
5. finish off with a clove hitch, pulled very tightly, round the crossbar.