Make concrete DIY ring cones. I would color one section of the concrete magenta when mixing it to have a more stable pattern rather than painting it.
DIY Cement Magnets using an ice cube tray - from 22 Seriously Cool Cement Projects You Can Make At Home
DIY : Molded Concrete Planters by Hairstyle Tutorials
DIY Concrete Lightbulb Hooks or drawer pulls: Fill light bulbs with cement, tapping to release air bubbles. Stick screw head or threaded drawer hardware into cement. Break and remove glass.