I don't have a fence, but like this idea. Find old windows, replace the glass with mirrors and put these on your fence (if you can). The mirrored image of your garden on the fence will make your yard look bigger. It's an easy trick!
Dishfunctional Designs: The Upcycled Garden Using Recycled Salvaged Materials In Your Garden - Old window frames with crystals form unique garden divider - I think several of these could create magical place for the kids