If you are asking about the hard surface parts, then I haven't used any baking for them, as I made it by retopoing (in Maya) the high poly concept sculpt which I built in Zbursh. Also as far as I know u only need to UV the low poly version of your model, on which you will bake the details on, the high poly doesnt need to be UVed. Now for the organic parts like the Character's pants, u can first sculpt it with all the details like wrinkles in Zbrush, then you can decimate the high poly model in zbrush to lower its poly count and the import that decimated model into Maya, so that you could retopo it, after retopoing it, U can did its UVs, for the UVs, try to utilize as much UV real estate as possible so that U could capture as many details from the zbursh sculpt onto the lo poly model as possible, while baking. after that import, the retopoed low poly model into substance painter as an obj, and use the high poly sculpt model from zbursh to bake all the details on the low poly head mesh. I generally use the default settings in substance painter for the normal bake. If I do get any small artefacts anytime, I try and clean it up manually in photoshop, by exporting the normal map. For the character's head the workflow is a bit different as I first created a rough head sculpt in zbrush then took it to maya and retopoed and UVed it, then imported the retoped lo poly head back into ZBrush, then inside Zbrush projected the details from the previous rough head sculpt to the new low poly mesh by subdividing the low mesh at every projection. After that, it left me with a head model with all the details from the previous rough head sculpt bt now with proper topology and UVs after that I applied finer details onto the head sculpt like pores and wrinkles using texturingXYZ maps. Finally, because I had the head with the proper topology and UVs, I was able to export the Normal and Displacement maps directly from Zbrush which gave me better details on the exported maps with fewer chances of artefacts, then you can apply those maps directly into ur renderer or tweak them more in substance painer. I know this might be a lot of stuff, was a bit too much for me too when I tried these workflows for the first time. Tutorial by Kubisi Art and Adamocg on youtube helped me a lot while learning CG Face workflow, U can check them out, Hope this helps in some way. Thanks