I first saw the braided hex nut bracelet over at HonestlyWTF. I think nuts in jewelry are just hot. The bracelets are very easy to do.
I did some just with knotted ends and one with a lock. All you need is some leash, I used nylon, some nuts and some kind of lock if you want. You can do these with all kinds of twine in cotton or leather etc. I like nylon, because it's durable and doesn't start looking worn fast like cotton does.
One you cut the leash into three pieces.If you just want knots at the ends tie a nut and if you want a lock burn the ends so they melts and glue the ends into one end of the lock.
Start braiding very firmly, holding it all in place with your tumbs.
Start braiding in the nuts, putting in a new nut every time you cross over the leash. Stop when you have the amount of nuts you want. Burn the ends so they melts and glue the ends into the other half of the lock.
Voila - your bracelet is done!