A foot, huh.
When are you doing 12/12 ?
Take the clone right BELOW a node, but with at least 1 or 2 above, that will become the new cola.
Roll it in dry papper towel then zip lock sandwich bag it. Can store in the refrig for 4 weeks like this too, just put it in the crisper/produce drawer.
When you're read to plant it, cut again at 45 degree ACROSS the node, dip and plant.
The reason I suggest across a node is because since it IS/WAS a node, more hormones congregate there.
Trim all fan leaves above the medium IN HALF, to slow transpiration and force the clone to focus on root production for survival.