Stages in square lashing – invaluable for shelter building and making camp equipment
1. Begin with a clove hitch and then lash the string alternately above and below both sticks.
2. Frapping to tighten the lashing. After 3-4 circuits make a full turn around one stick and circuit the string a couple of times between the two sticks going above different sticks from stage 1.
3. Finnish off with a round turn and a clove hitch.
To extend or practice this, see this post on natural weaving.