I want to tell you about a simple but effective method by which you can make pictures for your game.
1.1. Photograph what you need IRL (in real life) or
1.2. Upload photos from the site on which there is a section with free photos (Dreamstime, Free Digital Photos, Free Images etc.).
2. Upload GIMP (program like Photoshop but free) http://www.gimp.org/
3. Upload plugin G’MIC for GIMP. http://gmic.eu/gimp.shtml
After all of this, you can find the plugin G’MIC on the bottom line of the “filter” tab.
P.s. Use the “smooth dreaming” filter in this plugin to make similar effect.