Cunnyrim Starterkit

This guide assumes you have basic knowledge of installing mods, xedit, bodyslide, and are capable of changing individual files inside mod folders

De-potatofication

The non-adult characters in Vanilla Skyrim look like potatoes, but we can change that, and we have options.

RS Children: Goes for a lore friendly look and has a lot of patches for other mods and NPC overhauls. If you are going to use this mod you will have to replace the bodymesh, the skin with a compatible skin, and the skeleton with XPMSSE. To do this you will need to unpack the BSAs, and find the files in the actors/character/ranaline directory. A UNP based patch exists in Anubs animations (linked below)

HPL: Goes for a semi-realistic-semi-anime look. Questionable compatibility with AE 1.6.640, UNP based and works out of the box. There are UNP bodyslides available and 3BA bodyslides available, as well as a replacer.
I recommend getting the bodyslides for any of the options in this section, that is specifically the CalienteTools/Bodyslide/SliderPresets files, they can be installed like any other mod

Elin Race: Anime, in Skyrim. Player only, FOMOD options for body type, skin mods may need a patch (guide on the mod page in modders section). Recommend vanilla scale and either player.setscale 0.8 in game or xedit to change race size to 0.8. Recommended to use in tandem with another mod in this section for NPC.

There are other options but these are the ones that work best and are most stable.

Skin Textures

The best skin texture is Diamond Skin. It is available for both CBBE and UNP based bodies and has very good options for small breasts/flat characters. Some other skins may work as well, mostly ones based on Fair Skin Complexion or without heavy underboob shading.

Framework

Now that you have your body working in game and it looks the way you want, you probably want SexLab. This version will allow any actor participate in scenes, unlike the version from Loverslab.

SLAL is going to be essential for using non-default animations in SexLab scenes, and you will need it if you want to use animations that line up properly with smaller scale actors.

xxsUtility is another useful tool that will tell SexLab which kind of animations are available for the actors in a given scene, making sure that 1.0 scale and 0.8 scale actors will only use animations designed for them. This is also included in Anubs Animation packs below.

There are many SexLab related mods that have been patched for compatibility. There is a list of them here but not all of them will work with all versions of Skyrim!

Animations

There are two main producers of animations for 0.8 scale actors. Anubs and Billyy. You can acquire both of their animations on their respective paid platforms. You can find their animations from leaks, but they are likely to be outdated. Billyy from Kemono, Anubs from f95zone.
Anubs animations seem to get taken down after a certain amount of time, if these are dead, you can hopefully find them by searching f95
Another animation pack that is considerably dated and kind of jank is FunnyBiz, but it is the only pack I know of with necro, sleeping and other more extreme animations.

After installing these mods in your mod manager and with FNIS/Nemesis, you need to register them in game with the SLAL MCM. The more animations you have the longer this will take, and you cannot close the menu or tab out of the game while this is happening. Bring popcorn.

Honorable Mentions

Obody. Just replace the body mesh in your replacer mod with your body mod built to zeroed sliders with morphs enabled, then build all your outfits with zeroed with morphs enabled, and your smaller characters will be able to wear any clothing. Requires setting bodyslide preset in game with O key but will add a large amount of variety to your game world. Highly configurable

Cosplay Pack. Adds a lot of cute outfits and accessories. Also available in BHUNP conversion.

EFF. Take anyone you want on your adventures with you.

Don't forget to check out the mods listed here, there's a lot of them and some are worse than others and some do not work at all, but it's an active modding community dedicated to cunny. Check the forum as well, you might find your new favorite.