Flower beds, driveways, and walkways can often be better defined by the use of Belgium blocks or paver edgers.  The pavers are made from colored concrete.  Belgium  block is made from natural granite (more expensive).  The beds below show EP Henry Edgers being used to compliment and define the beds.

The edgers add a smooth appealing line along the bed.

 Edgers can also be used to make circles around flowerbeds. 

The trick of making edger circles is  to have the first brick installed butt up against the last brick installed with no gap.

The following are blocks used as edgers to border around the house.

This wall butts right up against a french drain that is covered in Delaware river rock.  The drain goes around to the front of the house and protects the bed from wash out due to the downspout near the entrance to the house.