I’ve used two methods when working with artists. The first one was telling them what to do and then pointing out “flaws” in their work and ignoring their recommendations and then eventually realizing that (1) they have quite a bit more experience on that stuff than I do and (2) this approach doesn’t work. I sort of tried to keep the control over creative stuff, and could not let go. End result: time wasted in communicating the vision back and forth, poorer quality of work.
The next method worked better: giving ideas/concepts/videos/pointers to material that described what kind of style I was looking, and then told them to “use your artistic freedom” to get it done. This has worked wonders: this resulted in much less time needed for communication and more motivated artist who will surprise you with the quality of his work*.
Let the artists do their job. That’s why you hired them.
* Bonus tip: he’ll also surprise you with the “hours spent” sum if you don’t have any control over resources that he is supposed to use on the work.