How to use sliders of the face generator separately one from another.

Is there some kind of Mod or INI tweak ?

I don't think you can use the sliders separately - one adjustment affects another. The face gen has long been a source of irritation. I believe the consensus is to do the best you can and then download a mod or two to fix it afterwards. I'm using http://www.tesnexus.com/downloads/file.php?id=5643, http://www.tesnexus.com/downloads/file.php?id=6611 and Enayla's http://www.tesnexus.com/downloads/file.php?id=14805. These will fix the face textures of everybody in-game - NPC's and PC's.

Beware of those links: TES Nexus is having problems right now with ads having malware. Apparently everything is supposed to be clean, but Google still has them blacklisted.

I recall am mod that freed up the relationship between the sliders - but I'm waiting on Nexus to be clear before searching needlessly.

There is a mod that changes the way the sliders work, basically by adding numbers to them.

It's called Character Gen With Numbers, and you can download it http://www.tesnexus.com/downloads/file.php?id=2170.

I find it makes the process a little more precise.

Can't be done with 'ordinary' mod, since it's Facegen SDK issue. If you wonder what I mean, grab any standalone Facegen(you can get free demo version of Facegen Modeller from http://www.facegen.com), then try to fiddle with sliders.

How do you port a face from Facegen Modeller to the game?

You can use Facegen to Oblivion converter(search for that...), but the result usually depends on what head mesh your character uses. Stock human head mesh and Head06 base mesh give the best result, while some popular custom head meshes, like idkrrr's meshes can give pretty bad result.

Found it ... Haven't used it but i claims to reset the sliders in face gen. http://www.tesnexus.com/downloads/file.php?id=9119
Also states it will conflict with race mods, but that may be load order dependent and at least the info is in the esp.

I found out that facegen2Oblivion converter works best with the stock human heads (Imperial, breton, nord, redguard) and 2 of the elf races (dunmer and bosmer), but for some reason gets distorted when converting the facegen file to High Elves and Orcs, and really disasterous when converting over to Khajiits and Argonians!!! So just stick with Humans and Elves and you should do fine (with only some last minute tweaks at most) when using FG2OB converter!