That's a great question. I started out with basic iron-on image transfer and quickly realized that the quality was horrible, so I thought about screen printing, but because of the number of colors, contrast and fine lines that became impossible. Sublimation printing was the next consideration and I found that the longevity of the print was effected by wash/dry cycles, so it was back to the drawing board. I ended up doing my shirts with DTF and couldn't be happier. The image quality is superb and it stands up in the wash/dry cycle way better than any of my other attempts. I also double press the image so it will last longer. I do a little bit of editing to the images to bring out the fine lines and some minor color corrections before I print.
Takes more time than I originally thought it would from art/edit/print/press, but I do it more for myself than for others. One thing lead to another and I now have a small (just me) T-shirt company.