This is the way a lot of my tickling art starts out looking, alll of my tickling art so far has been graphite pencil, charcoal, or black ink. With the ink ones there are rough pencil sketches they started out as, once I felt that I had the basic drawing I wanted to do sketched out in pencil, I would lay another paper over the sketch, trace the basic outline of the drawing in ink, then carefully begin shading in ink. With my pencil and charcoal drawings, the process was really the same, although often I just continued on to shading the initial sketch in pencil/charcoal on the same paper, then concealed any eraser lines in the background by making the whole background of the sketch black/dark gray that would fade to lighter gray at the edges of the paper, something I learned to do from drawing black and white portraits. Ink is tough bc if you over-shade or slip and draw a line of the image in the wrong place, there's no erasing
on one of my ink drawings I didn't feel like starting again with shading, but I felt that I over-shaded the bottoms of my male Lee's feet, and just told myself I guess his soles must have been a bit dirty
I would love to see the completed image or images you have in mind for this scene, and the sketch does very well at suggesting movement/facial expression and the way her feet curl into the tounges are really good, and her dress suggests this is a sort of medieval torture scene.