If you know how to do a rainbow loom fishtail bracelet then you will have no trouble with this. It is the same as the fishtail, but it goes in a square.
Step 1: Choosing Your Colors
I recommend choosing at least two different colors, otherwise it could become difficult to tell which pieces to loop.
For this instructable I used three colors. Blue, yellow, and pink (respectively).
Step 3: Creating the Base
***Make sure you place the bands somewhere on the peg board that would allow the project to hang through the middle. If you have the base of the board below your pegs, there will be no where for your project to go and it will not work.
To begin, you must take your first color (mine is blue) and create a figure 8.
TIP: I find it easiest to put one end of the band around a peg and THEN twist it before wrapping it to the other side. Of course, you can wrap it around your fingers first if you prefer.
Next, place another figure 8 perpendicular to the first, another perpendicular to the second, and one more to complete the square (see pictures).
Step 4: Adding a Level
Take your next color and create a square on top of your base.
Step 5: One More Layer
Step 6: Looping
Like with the fishtail pattern, you now loop the bottom layer over the peg and to the middle. Do this on all sides.
(See pictures for clarification.)