These 2' x 3' signs are being printed as I type. Much of the Birch Aquarium signage that I design and mount aren't even used in exhibits, but are for special events, such as this annual Nierenberg Award event. I was given a poster designed by the SIO (Scripps Institute of Oceanography, of which the Birch is a part of) graphic artist, and I had to reconfigure it to make direction and instructional signage.
Check out the original poster design to the left. How many fonts do you see? OK, it's a little hard to distinguish them at so low resolution, but personally, I like to keep font types to a minimum. I otherwise tried to keep to the same style, and stuck with the same color scheme (I would've gone with brighter colors, otherwise). There are not many design elements, so I pulled out the star shape and played that up to make my posters more interesting.