I start with a very detailed sketch. I try to not just outline but also shade as much as possible. Unfortunately, my scanner "ate" most of the shading here.
Decide on a color scheme... At this stage I don't worry about being neat and precise as I will be adding layers and more layers of paint later on.
Paint the background, down to the very last detail. Start "shaping" face and body with color pencils. I find it easier to do skin with color pencils rather than with paint. This is a safer method for me - I color skin with pencils and then lightly blend with either water or very watered down paint.
At this stage I was struggling with the fish head so I have painted over the head and tail. Originally they were white with red spots. I definitely prefer the final version. I've used watered down white paint to blend color pencils to create smooth skin texture.
Tadaaaa! Only some seven or eight hours later the pretty (if a little snooty) Mermaid girl is finished :)
The print is now available in my Etsy shop prints