iPhone 5 case, $27.50, by Leese Design, purlsoho.com
Backstitch: Insert needle from wrong side, coming out at 1. Insert at 2; pull out at 3. Insert again at 1, and pull out past 3, creating equal stitches. Insert at 3, and continue.
Cross-stitch: Using phone case’s perforations as a guide, create a row of diagonal lines, then stitch back over the row, making Xs.