The TKB books actually cover a number of cuffs and shackles. I'm sure JD could suggest a few of them.
One that I found quite by accident is, believe it or not, the Chinese Button/Lanyard knot. Still learning so fogive me if I use the wrong terminology. Tie the knot at the middle, as if doing it like a button. If you look at the top of the knot, you have three bights. The center bight should be the middle of the entire rope. The two outer bights however, drop down through the knot, leading to the ends of the rope. You could loosen up these bights to form a pair of loops. Slip the loops over the person's hands, pull as tight as needed, and secure with a simple knot underneath, square knot for instance.
I know it doesn't make for a particularly interesting or decorative knot, I prefer the cuffs that look like a blood knot with a bight at each end, but I did think it was an interesting use of the Chinese button knot.