I have my gardens bordered with bricks. I put sand under them to help with setting them level. I also put the black plastic edging outside them to keep grass from growing into the garden. DH prefers the brick edging over a cut edging since he can run the mower wheels on the brick to create a tidy edge.

In this photo you can see the edging on the closest end of the bed. The black edging is well hidden by the grass, and the brick edging is relatively unobtrusive.