Press a 1/2-inch fold along the top and bottom (the long edges) of the pocket piece, toward the wrong side of the fabric.

Then press folds along the right and left sides (the short sides) 1/2-inch each, towards the wrong side.

Repeat these two steps once and pin all the edges down.

Sew along all four sides with a 3/8-inch seam allowance.

Fold the apron and the pocket in half lengthwise (this will help the pocket to be well centered). Place the pockets' top right corner 4-inches from where the tie comes out at the waist and it's right edge 4.5-inches from the apron edge as shown above.  

Pin the pocket in this position and unfold. The pin the left and bottom edges. You don't need to pin the top, as you will not be sewing the top shut.

Sew the pocket using a 3/8-inch seam allowance, along the previous seam. Make sure not to sew the top!

Mark 3.5-inches from the left side of the pocket and then 3.5-inches to the left of the previous mark. Pin the pocket down to the apron in a few places between the marks.

Sew along the marks to make the pocket divisions, for your spatula and other tools. Make sure to backstitch these seams.

You're all done!

Happy 4th!