Here you are one of the best drawings I did for the mermay challenge (that btw, I still have to finish). I merged two mermaids in one drawing to complete to days in one.
I used a photo I saw on facebook as a reference to draw to koi mersonas. I started sketching the pose, then I did the lineart. The final and though part was coloring: the watercolor kept going out from the borders and spoiled all over the sheet.