Before you read this, make sure you read all of it .....
I get better results without these installed ...
5. Install bg2408's High Elf Fix
6. Install IFT & AFT
7. Install Natural Faces
8. Install Better Redguards (with the included textures)
Also have a read of Luchair's Body Seam Reducer instructions again, first thing to note is the included textures even though you think they are HGEC, are actually modified versions of Ozmo's textures, so work better (on my desktop setup anyway) overwriting Ozmos texture set.
I dont use them on the laptop, just EVE and no Body Seam Reducer (on the laptop I use OFF instead)
The 3 meshes in Luchair's Body Seam Reducer work best on player character, with only slight adjustments of sliders.
For NPC's (And Player Character) - the_philanthropy has taken Luchaires idea to a new level with http://www.tesnexus.com/downloads/file.php?id=35487. It includes his version of the same three egt's, plus just under 4000 more files.
He mentions a new game start can affect all in-game NPC's too, BUT your mileage may vary .... Read the warning reference starting a new game with them and subsequently removing them afterwards, and also reference playing an on-going game to which you add these. Best scenario is to start a new game with them installed - The caveat being if you remove them at a later date your continued game afterwards may have strange discolourations.
Also note I found they dont work too well with Ozmos for NPC's, as they do with EVE (which is why I still use Luchaires on the desktop)
After quite a bit of experimenting to get the closest match of head and body for all races on our two machine setups, I ended up with EVE plus OFF on the laptop, and Ozmo's plus Luchaires (and modified Ozmo textures included) on the desktop.
Beasts are just a case of finding whats best for you (but also bearing in mind your basic male and female body types and clothing armour designed for them - AlienSlofs Better Beasts for example are brilliant, but aswell as Rob Male you need Rob Female for them, and Slof takes no prisoners when approached about conversions to other female body types, its not going to happen) - All of the above can be upset by your graphics card and settings too...
Nightmare subject to be honest and I dont think theres one tried and true solution for everyone. So have a good study before installing any suggestions

Oh and before I finish, I think I remember IFT (or it could be Natural faces - cant remember which) work better with F-INev - I think it was someone on CanadianIce&Howndogs site that said Enayla designed one to work with the other, so that head and neck tones matched more closely the body. Edit: Enaylas face textures are additional to these; You install either IFT or Natural Faces, then overwrite that with Enayla's
Edit: Forgot to mention - The best seam reduction I have ever seen is Luchaires The Girl Next Door (TGND). She includes female oblivion and shivering isles clothing/armour modified for TGND, and has created a fair few adaptations of armour like Gizmodians Shell of the Artifice. The body part of TGND comprises just meshes - To which you add your favourite body/head textures (so you still have to find the right combination of a HGEC compatible texture setup for it), but the mesh matching at the neck, wrist and ankle are perfect - Unfortunately she did not get much support for conversions and seems to have given up for now. I had to bow to popular demand in my house because I have three lady players wanted the goddess store back
, so we use EVE now.
Edit2: In-case you are curious - The problem with The Goddess Store and TGND is TGND has smaller wrists and ankles. So with some of the items at the store designed for Exnem/HGEC you can get a difference of size at the wrist/ankle causing a gap. If you are happy with just what Luchaire and Kalia have spent many hours working on, and the conversions, its brilliant. But imagine trying to convert the Goddess store to TGND .... I dont think its going to happen. I think thats one of the main reasons TGND did not take off, and the fact that TESNexus is buxom wench biased.