My definitions (I don't know what the proper terms are so I gave them my own names) -
Point - The end of the leather farthest away from you
Bottom - The end of the leather closest to you you
Bow - The opening made when you push two strips to the side
Practice on a strip about 2'-3' long. Longer than that and it gets really confusing as to what is what. Shorter and it's not worth the trouble.
A leather strip about 3/4" wide is perfect. Slit it into 1/4" strips being sure to leave 1/4" - 1/2" at the ends.
Work the leather bending it back and fourth until it's soft and flexible.
Step 1: Marking the Leather
Step 2: Cutting the Leather.
I found the best method for me was to push the point thru the leather into a piece of scrap wood then very slowly and carefully pull the leather thru the knife instead of moving the knife.
Step 3: Starting Position.
Step 4: Starting to Braid
Step 5: Pull the Point Thru the Bow
Step 6: Second Braid
Step 7: Continue
Continue to alternate the left braid and then the right braid until you finish the strip. If the braid is unbalanced at the end you should add one or take away one.
If it's not smoothly braided you can work it back and forth to even out the tightness of the braids.
This last photo shows a braid finished but not smoothed out.
If you want to unbraid it just reverse the steps you used.