Make up shoot. How to light?

I've got a make up shoot tomorrow and was wondering what's the best wat to light it? 1 light to make the face more 3D shaped or 2 lights to just make if flat but even? I also have a ring flash should I use this?

have a look at the techniques used to achieve this:
http://strobist.blogsp​ot.com …umiquest-softbox-iii.html

so that's 3 lights (including sunlight)
diffused /softboxed flash, camera left - oncamera fill flash and sunlight behind subject.

that or look at http://digitalarticula​tion.deviantart.com …g-Setups-for-Shots-I-took
which is some shots setup and technicalities explained.

is that what you were after?

the point of off camera flash is to not have flat lighting. Might as welll just use the on board camera flash. You can do fine with 2 lights for sure.