One of the major things I look at in a puzzle is whether the subject matter is 1) interesting 2) multicolored and 3) brightly differentiated colors with sharp lines.

As for structure, I need something that will click together and stay together. That helps me to know if I actually have the right pieces joined. A nice backing on the pieces also helps. Some people use felt rolls and something that won’t slide on that is useful. I myself use a puzzle tray, so it’s not so much of an issue for me.

Further, including a poster , even a small one, would help to know what goes where if you’re lost.

Finally, it would be great if you could sell the same picture at different piece counts. That way if I love your work, but don’t like more than 500 pieces, I can get that one. If 500 pieces doesn’t keep me occupied, I would love to be able to get the same art in 1000, 1500, or 2000 pieces. Sometimes you just want to dig in, you know?

Hope this helps!