I did a tutorial on lips for ~HaphazardousPenguin! It's for Paint Tool Sai, but you can apply the same shading principles to other programs as well as traditional art. For traditional art (shading with a graphite pencil) use an eraser for the luminosity and make your lip lines slightly thinner c:
By the way, I like your icon
And shit thank you ;w;
And you're welcome! c: I am very much a Strider fan. Believe me. My tumblr blog is all Strider :u
Thanks!