just chatgpt, the original looks amazing, to be honest; I don't want to show it cause I know you'll muthas have your AI upscalers at the ready!
I find you get pretty good results with illustrator and a screen tablet, though; that's my method of madness.
I don't mind taking a relaxing 10 hours to do a good trace drawing, to then give it about 10-20 slogans to then upload each of the slogans with the design. Makes it a bit easier than just doing one great drawing, and listing it in the hope of people buying it, the more the merrier as we all know. 12 designs for a couple of days work works well for me. Its not far off what I used to create when I done well at merch before, but now my designs are the best I can draw with my ability instead of just text and a siloutte all the time. If it wasn't for ai I wouldn't be able to draw as well to be honest. Its only being good at tracing that has sparked my interest again in merch. Best of luck.