I really love doodling these whimsical little mandalas. I was initially inspired by Christine Mason Miller's book Ordinary Sparking Moments. Christine includes several inspiring designs in the backgrounds of her book.
I often refer to her book for ideas, but I've added my own flare a bit too. I started with a simple water color background and used a white gel pen for the designs. It's subtle. A black sharpie could also be beautiful and would provide more contrast.
I always start with a tiny circle. Just a bit more than a dot. Then I add a band around the circle. Maybe petals, loops, swirls or bars. Then another band around that. It's nice if some bands are close together and some have more space between them. Repeat, repeat, repeat! Expanding as far as desired.
Mandala is a Sanskrit word meaning circle. They are usually concentric designs and have a long history of use in various spiritual traditions. Looking at Google images or Pinterest or Flickr with the search term "mandala" could lead you down a deep deep inspiring rabbit hole. (Don't say I didn't warn you.)
I took a workshop about using mandalas in design and creative exploration. Here are a couple of images from my sketchbook. Gosh, I see they are dated 2008! Was it that long ago?
I really love this collage idea. Just cut similar size images and compose them in a circle.
I also love drawing tiny mandalas on these beautiful stones that come from the shore of Lake Ontario. These often get tossed in with birthday gifts to my arty friends.