In reply to colina:
To shank the rope, you first double it up to 2 strands, then 4 then 8 before making the loops. Although I think the guy in the video only goes to 4. When you unshank it, instead of pulling all the loops out and flaking it out, pull the loops out, then separate out the two groups of 4 strands, so you are reversing the final step before you put the loops in, before flaking it out. Sorry if this doesnt make sense it's easier to do than say.