Brick pavers make a simple, handsome border and work well as edging material. They're ideal for a wide border that keeps grass out of the garden, yet allows flowers etc. to spill over without intruding onto the grass.
Where the Grass is Greener! If you have no need for an open backyard, consider creating grassy pathways that wind around smaller garden beds. This is what really makes the garden look so special. Bridge does not need to be over water