Take one pile of "unusable" concrete waste left over from trampling march of urban sprawl.
Break into manageable pieces, and transport to "refining" facility.
Once there, add two heaping helpings of manual labor. (And yes, I mean HEAPING HELPINGS!)
And Voila! Beautiful, garden edging, complete with "Rustic" cobblestone-like appearance for that quaint English garden look!
Get out there and see what you can find to reuse. It feels great to have something beautiful for nothing, and to get a good feeling for helping the environment to boot!