Sew several pieces of felt scraps together to form a long narrow rectangle. With the dimensions 4inch by 18 inches. Sew the pieces together. Hem one narrow end of the stripe with a 1/2 inch seam allowance and made two straight stitches to make a firm hem.
Fold the rectangle up approximately 6 inches. The tips of the color pencils will peek out from the case when open, like in the photo above. To make a flap for the felt pencil case, fold it twice.
Now, when hemming the flap end sew two straight stitches 4 to 6 mm apart. Then turn the felt patchwork right-sides-together and sew together the two sides of the pencil case.
Simply fold the flap in half (lengthwise) and cut into the space between the straight stitches and cut a buttonhole. To keep the buttonhole from stretching, all you need to do is secure both ends of the buttonhole by short straight stitches.
One last thing to do: Stitch a button onto the case to close the flap. Since this is the last thing you do, it will be totally easy to test where the best place for the button is by closing the pencil case flap and see where you need it.