For about a year around 2013/2014 I provided all the bundle artwork for the guys at Indie Royale. Most of my work was to create the theme art for each bundle, usually based on the titles.
For the most part I used Inkscape to create these pieces, mostly drawn digitally in rough using MyPaint, occasionally in pencil or pen and scanned in. The biggest challenge was timing, often I would be asked to create the art at the last minute with a deadline no more than 12 to 24 hours away!
Here’s a slideshow covering most of these pieces.