At first the graphic designer has to break the process down into it's fundamental components. Which could be:
1) Discussion and Clear Comprehension of the Brief
2) Research and Collection of Information
3) Sketching
4) Execution and Experimentation
5) Finalization
6) Revision and Further Corrections
7) Submissions
Then self-analysis is required to figure out the current stage process. Project management soft-wares such as Trello could be helpful when it comes to tracking the progress. Hope this answers the question.
Companies usually like this reach out to you if you want to get signed up with them. You have to release songs and get recognized. Based on your talent and singing or rapping rate is how you get in.