I used estlcam. Just open a photo, black and white works best, it’s fairly straight forward from there. Once you get it the way you like it, close the settings window and then save it as a CNC file. Oh, it has to use an engraving bit. I think mine is a 3/8″ 60deg wood bit.
I painted the MDF first for a contrast. Going to cut it to size tonight and shoot it with come clear poly to keep it from absorbing moisture.