1) Print reference image and create a simple sketch from observation by measuring the angles of the watermelon with your pencil. Alternatively, transfer the image onto canvas.
2) Using a flat brush, work around your watermelon sketch to paint the background in Aqua.
3) Paint the flesh of the watermelon using a combination of Burgundy, Red, and Light Red.
4) Once the first layer is dry, use Black to paint the seeds.
5) Using a dry brush technique, lightly brush over the seeds with Red to create the illusion that the seeds are inside the fruit.
6) Working with a small round brush, use Buff White to paint the inside of the rind.
7) Finish by using Green and a small brush to paint the edges of the rind.