ProKnot cards in my work backpack for random knot tying practice (doesn't everyone?).
I figured it out. I didn't see before that I'd have to pass the entire guyline through the bend on the tie-out (d-ring) in order to make the larks head. Which sort of make these semi-permanent. For some odd reason I was thinking these guylines were the tie and un-tie type configuration like many others, but that's not the case.