I Do not recommend to use other people’s work as references. Or at least not as your main one.
Because their work has already been processed through their vision, and the risk it to copy instead of getting inspired. Especially if you don’t have developed your own style yet.
However, If you really like someone’s style and if you do so in a learning mindset to understand the techniques so you can adapt them to your own style and process and not just to copy/paste, in this case I’m all for it. Remember, the importance is to learn.
For instance, with Fanny Vergne’s workflow (Artist at Blizzard) I learned her techniques to create stylized hand-painted look textures.
Because I took some time to understand the process, I could adapt it to our production pipeline and create my own workflow at Gameloft Montreal. It would have been stupid to just copy/past the technique under real working conditions because we didn’t have the same goals. Whether it is about deadlines, artistic direction, levels of details, game style etc.
You see, you have to keep in mind that an artist have his/her own objective(s) just like you, and that is why he/she ends up with this style and workflow, so be smart and adapt.