To get a really fluffy kiss mouth that all guys just want to eat;) you can use several lipsticks, and thus get a more 3D feeling!
Dark lipstick at the edges.
Preferably a little closer to the mouth pores, then it looks like a more natural "shadow"
Lighter lipstick inside the dark pin.
"Blur" the edges a little.
Shimmery lipstick right in the middle of the lips.
Also works with lip gloss!