Flip-over curtains -- experiences?

Anyone made these? Have directions or proportions to share?

I am thinking this might be the solution to my "short stash"
situation. Picked up some clearanced sheer printed drapery a couple
years back. It's really cool: a Richloom multi print, batik-type
graphics with fish, leaves, spirals, other interesting shapes...and
not quite enough to do the windows in the house I picked up at
clearance in June.

TIA

--Karen D.
.