When I saw this question, I was tempted to answer with answer along the lines of
Don't use GIMP, this would be the wrong tool for the job.
No one mentioned GIMP but, I felt a urge to encourage people away from the tool (I like gimp but it wasn't the answer)
However, I did not because that answer would not stand alone. If that was the only answer it wouldn't solve the question. It might help them if some of the other answers provided recommendations, however, it can not, itself, be accepted.
Does the community agree that anti-recommendations have no place here?