I spent many, many hours working on my current loadout of appearance mods for males and females. It took a lot of trial and error and comparing files from every one to get to where I am at now (and I am sure I will be adding more!). It occurred to me that some lists and explanations of what each mod does might save other folks a lot of time and effort and frustration. So I started this topic.
First of all some basic tools. Paint.Net is a free graphics app that will let you open the .dds files that all the game's textures come as. Very handy for comparing the textures between mods. For Windows Vista, 7 or 8. Should work on 32 bit systems.
Nifskope is a free modelling program, that will let you open the .nif mesh files used by the game if you are curious.
!!!Some of these links are not work safe or kid safe!!!
I have spent a lot of time tweaking my appearance mod loadout for women (and for men too) So far what I am using is this, installed in this order (because some things overwrite parts of others):
Dimonized UNP Base Body - I deleted the two female body .nif files. That is because they not only one make all the female characters naked, but they change the body slider into nothing but a boob slider. So I essentially have the same body shape as the vanilla body, but get the higher res hands and feet. There are some high res body textures that comes with it, but almost all of them are completely overwritten by my other mods. There are underwear options with UNP, but I found one of them gives me CTDs. Which made me have to try an option to the optional underwear files. For me it was easier just to delete the two body .nifs.
Files: Meshes - femalebody_0.nif, femalebody_0.nif, femalebody_1.nif (I delete these two), femalefeet_0.nif, femalefeet_1.nif, femalehands_0.nif, femalehands_1.nif.
Textures - femalebody_1.dds, femalebody_1_msn.dds, femalebody_1_s.dds, femalebody_1_sk.dds, femalehands_1.dds, femalehands_1_msn.dds, femalehands_1_s.dds, femalehands_1_sk.dds.
Seamless UNP and Coverwomen #4 - This is the Seamless option to Coverwomen look #4. There are four looks, each with differing amounts of glam. #4 is the no-glam, normal look. The seamless UNP version of it is meant to reduce the neckseams that you get when using texture mods. Unlike the title, it is not really seamless. But it does help.
Files: Female Folder = femalehead.dds, femalehead_msn.dds, femalehead_s.dds. Race Folders = femalehead_msn.dds.
Sub Surface Full Body Map for Coverwomen and UNP UNPB bodies - What this does is work on those texture seams, and it does a very good job. I can still see a bit, but not very much after it.
Files: femalebody_1_sk.dds, femalehands_1_sk.dds, femalehead_sk.dds. (So this is overwriting parts of the UNP texture files, but not all of them).
Fitness Body (using the UNP Fitness Main Body - with optional Lesser Abs) - This mod makes the female bodies look more fit. It has different downloads for UNP and CBBE, and different flavors for each. Inside each rar you download are even more options. It all depends on how muscular you want to look.
Files: femalebody_1_msn.dds, femalehands_1_msn.dds. (note that this overwrites parts of the UNP body, but different parts than Sub Surface Full Body Map does, so these two mods play nice)
Women of Skyrim (with optional smooth faces for elves). Women of Skyrim adds a huge amount of detail to your character faces, to the level where you can see individual pores on their faces. It is not really a glam mod so much as it is a high detail mod.
Files: Female and Race Folders = femalehead_msn.dds. (Incompatibility warning! If you install this before Coverwomen it will be completely overwritten and do nothing. So it must be installed after Coverwomen.)
Numenume Female Brows. This one adds a lot of new eyebrow types to choose from in character generation. I think they are more realistic looking than the vanilla brows, and almost always use over the ones that came with the game. As with Detailed Lips, it does not overwrite anything, so it plays nice with your other mods.
These affect both male and female characters. The install order does not matter:
Natural Eyes - This is a texture replacer for the vanilla eyes. It makes them look a lot more vibrant, so you can actually tell what someone's eye color is!
Mystic Eyes - This adds some new fantasy-looking eyes. Lots of bright, almost glowing colors. Good for characters that are supposed to have an otherworldly look. Also plays nice with other eye mods like Natural Eyes.
Cherry's Eyes - also adds more nice eyes, and plays nice with Natural Eyes and Mystic Eyes.
Instead of SLF Hair, I have been using AOF Believable Hair -Female and Male for the texture of hair instead.
Eyebrows Match Hair. A nice little mod that makes your eyebrow color match your hair color. How could Bethesda have missed this!
For new hairstyles, I recently started using Apachii Sky Hair with the option Sky Hairs Female in addition to the base mod, and ShowRaceMenu Precache Killer to keep Apachii from crashing the game whenever I open the Race Menu. I also use Apachii Sky Hair Wigs for my custom races. It has some of the hairstyles from Apachii available as wigs, so using ShowRaceMenu is not necessary to use them.
I also use Ponytail Hairstyles, which plays nice with Apachii.
Here is a sample of Sofie Persephonesdottir with the mods above
Lucia Persephonesdottir
Finally, for Sausages alone I use this:
Better Males - Younger Faces Merged With Men By Geonox. There are a lot of options available, including nekkid and erect penii. I use the Younger Faces Merged With Men By Geonox, which keeps their underwear on, but their skin looking good.
Ralof is much happier with it. (Though he still needs a bath!)