I am a student of game art. When we make characters, we usually make the base model first (the low poly) and then export it to Sculpting programs such as Mudbox or ZBrush. It's easier to sculpt characters, even with very basic knowledge of the software. Now this is not written in stone, and you can chose whichever way you think is faster and convenient for you of course.
About clothes. Since for games, we rarely see the character changing attire (GTA, Hitman and few other games are exceptions), it's best to model the attire instead of the body details. For example, if you're character is only going to wear lose clothes like a shirt or jacket or something, then it's pointless to sculpt or model the inside of the character and then clothe it. Because you're never gonna see the bare torso of the character for most games, if the characters are wearing clothes.
But, if you want to make very tight clothes, then you can either sculpt or model the inside as well, and then Extract the mesh for the attire out of it the mesh (we do this in sculpting programs).
Garment maker is great for creating clothes alright. But if you're doing the model for games, delete the inside of the character that the clothes cover, after you're done with making clothes because you don't want to waste polygons that wont be seen in the game. Plus this will save time Unwrapping, texturing, and Skinning for animation.
This video by Arimus 3D is great start:
https://www.youtube.com/watch?v=F5NvwZEYxkA
This video shows how to use the garment maker:
https://www.youtube.com/watch?v=2rk26V3kH5I&t=23s
This video shows how facial animations are done, but there's no rigging shown. because each facial expression was sculpted individually inside Zbrush before bringing inside 3DS max:
https://www.youtube.com/watch?v=0XG1UJBfwW0
Feel free to criticize or ask more questions.
