I've been creating a character model as a learning exercise. It's supposed to be a simple <5k triangle model. I ran into an issue during the texturing phase.

Photoshoping the texture directly onto a low poly model didn't work very well. I think what I should have done was to create a high poly version first and use it to bake some shading and normal mapping onto a low poly version. But I just can't get my head around this concept.

High poly and bake maps I can do (sort of). But what's the work flow for converting a high poly model to low poly while keeping a compatible UV layout? How do I deal with hair cards when baking lighting? Turn them off and paint that shading by hand? Do alpha before the rest of the texture?

I'm using Maya, and I'd like to use/learn ZBrush at some point (after the high poly modelling stage I suppose?)

You dont need to keep the high and low uvs synced up for any reason, generally. When you bake down it will transfer all of the info to your low's uv map.

For hair "cards" i would suggest using a tiling texture/a section of your uvs that you instance for this purpose. It doesnt really need to have normals info persay even. This is probably the simplest thing you can do, i'm sure there are some more advanced solutions but i would stick with this for now.

If you've got some images to show what you've got so far, and/or some references to show what you're trying to accomplish, it would help out a ton.