The primary way I learned how to mix was watching professionals as an system tech for a large production company. I spent countless shows standing next to Audio Engineers from some of the biggest acts in the US. In the down time, I would ask them as many questions I could. Then I would apply what I learned the next time I was at the console.
Here is a video of the process that I go through when creating a mix for a full band. If you have any questions of comments, please leave them below. I hope this is helpful for you.