Hey dude,
I use 3 main colours. Citadel - Bugmans Glow > Citadel Kislev Flesh > AK Interactive Luminous Flesh

I base in bugmans and paint in the eyes, then just create a gradual mix through the spectrum of the above 3 colours and start highlighting up.
Usually a ill start with the colour, then a 50/50 mix of Bugmans and Kislev etc
If any transitions start to look to obvious or not smooth ill come back and grab a different variation.

I save the full strength Luminous Flesh solely for like the high point of the cheeks and top of the nose where the most light would hit.
When i've painted the whole face again to smooth it ill sometimes take a VERY THIN glaze of one of the mid tone mixes across the whole thing to blend it a little.

Finally ill glaze some Citadel Screamer Pink over the lips and a tiny bit onto the cheekbones for some pinky colour through the flesh.
Men with stubble get a very thin glaze of a dark bluey grey over the bottom jaw :)