 use some toned paper or create your own tone by using powdered pigment and shaving some pencil on top of the paper, draw in your droplet, erase a highlight on the high side, and then put a shadow on the backside of the drop. There's even a dark on the high side as well, and then start filling in colors around the highlight to make it pop more. It needs to look white, but on the backside of the drop, sometimes it goes all the way white, but a lot of times, transparently, it's just a lighter value of the main color. And then you can blend either with wet or dry blending, and your drop is all done.