Start with a solid green base. Allow time for it to dry. I like to put a top coat on top of my base color to prevent colors running together later, but that's an optional step.
Once the base is dry, carefully draw random lines in black using a small brush or stylus. Leave enough room between them to add in the stitches. Allow a little time for them to dry.
Draw two or three lines running perpendicular to the first lines you've drawn to create little stitches. Allow drying time and finish with a top coat!