I haven't done a lot of appearance modding, though I have half a dozen hair mods in the inactive folder for future PTs, partly because it seems like those are the ones that have had the most trouble with the DLCs and locking up, etc. I'm hoping that now that the final DLC is in place that those are stabilizing because I really want eyebrow mods at least, lol.
Hair mods and face retextures are as stable as they get by now, unless BW decides to launch another mini-patch at some point... but I doubt it. They already released the fix patch for Trespasser, and I think that was all they intended to do with this game.
I'm using replacers for virtually every hair but the buzzcuts (because I like seeing the NPCs with good hair too), and haven't had any issues. The only place where you will inevitably have issues is in Trespasser, but that breaks so many mods that I've found it easier to just have a side folder with only the minimal mods that actually work in it and swap it around in when I play through that one, than to keep moving mods in and out of the main mod folder all the time.
Anyway here's some modding tips no one asked for.
The easiest way I've found to work with tons of possibly conflicting mods is to have one universal Mods folders, where you put mods that you will use in every character you play, and separate smaller folders with each character's name, where you throw in the mods that you will only use with that character. So if you use three different ponytail replacers with each of your characters, you put it the chara's folder, but if you use one replacer for everyone, you put it in the universal folder. Same for unique PJs for different characters of the same race, face retextures, etc. I have my qunari/elf PJ replacers in the universal because those are the only ones I like so I use them through all characters, but I have a different PJ for each of my humans or dwarves, so those go in the character's folder, etc. So that universal folder you'll rarely have to touch, so you won't be meddling with so many mods each time you play a different character - you can just pop that character's unique folder in and out of the main one and rebuild your patch each time you feel like playing them, without rebuilding your entire mod folder aaaaaall over again.
At least that's what's been working for me. I find modding quite calming and therapeutic because I enjoy the process of downloading and classifying mods, making directories and subfolders, organizing them according to which playthrough they belong to, etc - but I know not everyone uses modding to satisfy their OCD. 