Here are some past dingbats I did for GreenPrints. They were done in Adobe Illustrator. I chose to use Illustrator because I can work really fast in that program (I've been teaching it for 10 years) and it has super crisp output. These guys were printed about the size of my thumbnail so clarity was really important.
I have done pencils and Painter for dingbats in the past but they usually didn't work out. It's easy too caught up in gradations and values and more time was spent rendering something that didn't show up or show up poorly.