How to make space creative?

We talk about this constantly as a church meeting in a school. Overall modern schools are sterile and bland making it a challenge for a church striving to be creative. We have used trussing with colored par cans, large (10' by 5') banners to convey info, made Chipotle-inspired coffee bars, huge inflatable for kids, and Ikea decorative strips acting as water...but we strive to continually up the creative experience.

Here are a few examples of idea of interesting additions to make a space pop: a large piece of notebook paper, countdown on concrete, images in water

(thanks Church Relevance)