Step-by-step:

Give your character a repellent appearance

1 When putting down your initial colours and values, don’t worry about keeping things tight. Painting beauty demands every feature be placed just right, so the less you’re striving for beauty the less you should worry about clean lines and symmetry. In fact, making all of the features smooth and symmetrical is something you should actively avoid. 2 High- key art tends to feel soft and light because of its lack of contrast, so adopt the inverse of that idea to create more uncomfortable images. You don’t need to cover everything in shadow, though, because that can also soften a lot of edges. Quick jumps from light to dark add tension to an area, so don’t be shy when aging a face. Dark lines mean deep wrinkles. 3 Signs of decay are an easy way to make people look creepier. Drawing an uncomfortable posture, removing teeth, exaggerating the ears and nose, spotty patches of hair (not to mention hair growing in strange places), and pretty much anything rotting, will enhance the effect. Avoid giving your character anything that implies a personal cleanliness routine. 4 Again, the idea is to make the character appear as unhygienic as possible. If it looks like they’ve showered any time soon, make them a little more repulsive with some appropriate textures. You can make some areas of the skin slippery and slimy, have some mucus running out of a few orifices, or add lots of pores and bumps to the skin. Have fun with those icky details!