Yes 12 will be fine. When I first started out I had about the same amount of designs. These were printed out and pinned to a board. I thought that they were rubbish as they were basic designs and I've seen so much better yet people would come up and look at my board and be like 'wow there amazing' and that encourages you. Some will be more popular than others and you learn as you go along to take out old ones and replace with more popular ones. Check me out sounding like an old pro.
Chris
Chris