Hi there!
I really enjoyed this small and simple class and was inspired to make my own badge. I couldn't decide for a city, so I went for a travelling-motive instead.
I kept close to the design in the video and therefore didn't have to start with a sketch. I made several color samples, though:

I decided to go for the blue one. Unfortunately, Illustrator left my high and dry on the grunge texture-part. I cannot tell why I was not able to use the grunge. But it seems the texture was too much for the program to manage. It got stuck all the time, although my computer works perfectly fine, otherwise. I could have gone for Photoshop, but that somehow spoils the fun ;-)
So, here it is:

And here's some fun play with some (could be more, though) rough edge effect:
