Sometimes you need a clove hitch *fast* but you have only one hand free. Here's a quick way to tie a one handed clove hitch...
Step #1 Clip into the carabiner as usual so that the rope runs from your harness (H) through the carabiner and down to the belayer (A). Reach over and grab the rope going to the belayer, thumbs down.
Step #2 Flip your hand over, thumbs up and you'll find yourself holding a bight (L) of rope from the belayer.
Step #3 Clip the bight (L) of rope from the belayer into the carabiner to form the clove hitch. You can easily undo the clove hitch by unclipping bight (L) to continue climbing. NOTE: If you inspect the clove hitch carefully, you'll notice that the rope from your harness enters the clove hitch away from you. This is a little awkward, but that's one of the trade-offs of tying the clove hitch this way.