This technique makes a round crocheted cord which looks like a knitted I-Cord, but it is made with a crochet hook. You can make it as thick as you want by using 2 or more strands of yarn held together, and using any hook size desired.
1) Ch 2. Pull up loop in 2nd ch from hook.
2) Remove hook from first loop (pinching the loop between your fingers so that it doesn't come loose). Yo, draw loop through the loop remaining on hk.
3) Re-insert hook into first loop, yo, draw loop through.
4) Repeat row 2 instructions
5) Repeat row 3 instructions
6- ) Continue to repeat steps 2 and 3 until the cord is the length you desire. Finish by drawing a loop through both loops; end off.