My tote lining fabrics were already cut to size. I took ONE lining fabric and laid it right side up, then centered the pocket. The raw edge faces the center of the lining, and the folded edge extends off the bottom. Sew along the raw edge of the pocket. (Note: this is done BEFORE sewing the lining fabrics together.)
Fold the pocket up and press. Sew the two short edges to the lining fabric with a narrow top stitch to secure. I recommend backstitching at the beginning and end of each seam for strength. Now you have a pocket!
I wanted to make a divider in my pocket to hold a pencil, so I measured 2 inches in from the right side of the pocket, and drew a chalk line. Then I sewed right on the line, creating a narrow pocket.
Here you can see how the pocket will work. Now you can go ahead and sew the two lining pieces together, and finish your tote!
Here is how the pocket looks in the finished tote: