These 3 sets of five logos each are used to help orient aquarium guests participating in "Explore It!", a family-based program. The top set was used for Explore It! Tide Pools, the middle set Explore It! Ocean Potions (things to do with ocean chemistry) and the last set which I just made, Explore It! Corals. You'll see them on activity station signs and on the guide/work sheet hand out.

I wanted them to be easily recognizable, visually simple using black and white and only one other color, and to represent a concept or subject (pre-determined by Education people at the aquarium). A part of the challenge is designating black, white, and color areas, so as to create a balanced composition within a square frame. Some subjects, such as the ink-squirting octopus and clown fish, are easier to color-designate than others.

I use Illustrator exclusively to make these, and they do wind up looking Illustrator-y. Hmm, what do I mean by that... it's the quality of not being hand drawn; the images are smooth and slick; each shape has a blocky presence. But that's OK given the purpose of the icons. Below, you can see how they're used in station signs and procedure signs.
P.S. the font is "Junegull" from my favorite free font website: