I bought this little round frame in a cheap store recently and this is what I did with it...
It measures about 10cms (4") across. I first sealed the wood with gesso then painted it with some dark brown textured paint, it has a gritty texture (see 2nd photo) and dries quite quickly.
I used a Kanban Steampunk image for the centre and then added a few cogs (by Fernli Designs) that I had painted in metallic bronze and gold.
Simple and effective I think...and a nice little hanging for a little boys bedroom.