I had a pad of blank postcards laying around for awhile, and I weeded through our collection of dried out ballpoint pens. I started with a simple concept for each card and built up the design around that, adding new ideas as the pictures developed. So basically, a doodle.
I had a lot of fun experimenting with interesting designs. Some I like better than others, and this "Spikes and Bubbles" card is my favourite. I should say something insightful about the juxtaposition of circles and lines, but the simple truth is the idea of popping bubbles amuses me far more than it should.
All of these are currently available through Etsy.