For a bracelet the cord will be in a loop and if you tie the normal fisherman's knot and pull the ends apart the 2 individual knots will pull apart and the loop will get smaller and if you pull the ends within the loop the loop will get bigger. This is also really dangerous if used for a necklace as there is nothing to stop the loop from getting smaller and smaller with obvious results.
This is no use for a bracelet as the loop can get too small as I mentioned above and there is now way for the loop to lock so that it doesn't open up accidentally.
This Instructable will show you how to tie the reverse sliding knot, how you finish the ends of the cord is up to this is just to show how the knot is tied.
Step 1: An Overview of the Knot.
As with everything you will need to experiment with cord length as the thicker the cord the more cord will be lost in the overhand knots.
The tail length will determine how much the knots slide apart to make the loop bigger.
Step 2: Tying the First Overhand Knot
Step 3: Getting the Length
Step 4: Tying the Second Overhand Knot
Step 5: The Two Knots
Step 6: Passing the First Tail Through
Step 7: Passing the Second Tail Through
Step 8: Finished!
You will need to tie stopper knots on the ends of the tails to stop the free end passing through the overhand knots then you pull the knots apart.
Finally you will need to experiment with cord length to get the optimal length for the tails, too short and the loop wont open up enough and too long the tails will be a nuisance. When used as a bracelet the tails can be tucked under the loop for extra security and to keep them out of the way.
This is my first Instructable too!!