My answer is one you probably won't like... Don't add highlights to your texture. Do lips come with highlights? Nope. So, nor should your texture. :) If you want them to look glossy or reflective, use the material settings under the render menu.

Oh ok, well that makes my life easier...Cheers ST

No prob. :)

claire i agree with samtherapy :-) i got your IM and i'm looking at some makeup photos...

The dodge/burn tool works great for hair highlights, but I think I'd single-pixel dot and only slightly smudge lipstick highlights if I was using them....Those little vertical lines on lips break up highlights a lot. Having a darker line right next to a reflected highlight makes it seem much brighter and sharper, if you know what I mean. Most of the time, I agree that they shouldn't be painted on, but I've never succeeded in getting that really high-gloss sparkle that lipgloss gives with any of the settings that I've tried in Poser 4, so I add it with white in Photoshop :)