That really depends. My character creation process is very organic, it's only in a few rare cases that I develop them before they pop into the story. On first appearance they tend to be relatively flat and generic, but get more defined over consecutive drafts.
I don't keep character sheets or anything like it, though I work with such big casts that maybe it would be a good idea for me to do so. Sometimes I'll scribble down a pertinent detail and keep it around until I've committed it to memory. There comes a point where I've integrated a character so fully that I can't possibly forget what they look like.
As for how much detail I put into the description of each one, that is wildly inconsistent. Being a main character is no guarantee that you'll being rendered as anything more than a rough sketch, as far as appearance goes, whereas even the minorest of minor characters can get a paragraph or more of description. It's all about what I find interesting and visually striking, what adds some style and color to a given scene.
I don't usually mention things like eye color, or at least I don't belabor it; I might mention a given character's eyes as "dark" or "bright" here and there, but nothing beyond that. I make exceptions where a character has some unusual hue or something else going on, or if they have particularly soulful, expressive eyes I can use to convey their mood. Same with skin color, that typically gets a passing mention at best, though I use things like blushing and blanching fairly often. Exceptions get made for non-human races. I have a couple of silver-skinned races in my stories, for example. And in one story, I've got goblins running around. I trust the reader to see those as green (and it's no problem for me if they envision purple ones). Suffice it to refer to them as "the little green folk" once or twice. Again, an exception is made in the case of one particular named goblin character, who has something like vitiligo going on. That's just how that guy manifested. He has a number of features that make him stand out.
What I pay a lot more attention to is wardrobe and, to a lesser extent, hair. There's much more room for characterization in how people choose (or in some cases are made) to dress, whether it be for style or function, rather than what color their eyes or skin happen to be. I also just think clothing and armor is really fun, and it adds a lot of visual interest.
I also tend to make at least passing mention of things like height and build. It occurs to me that's quite important for the composition of a scene. As for likes and dislikes and such, if it doesn't arise naturally through the course of the story, it can't possibly be all that relevant. I like to think I know my characters well enough not to keep an encyclopedia of that sort of stuff.