Firstly you need to define how you will use the outdoor living space. Is it going to be a static area, purely for aesthetics or will you have children playing there? Will you be using it at night, or solely during daylight hours?
These factors will determine what you need and what you can actually place in your space.
For a static space, sculptures and water features work well. They provide a focal point and can be the source of the theme of your garden. The water feature also creates movement into a space that is static and creates a quiet calming sound of water flowing.
For an interactive space, pots are great as they keep the plants and flowers off the ground and are less likely to be stepped on.
Bench seats and seating sets are ideal in these areas as you can sit and enjoy your garden. The ideal situation for these seats is to have a solid ground with paving so the table and chairs remain level and don't wobble. Be sure to select a material that weathers well like cedar or teak timber or wrought iron. For a modern alternative Dedon furniture offers a stunning all weather water-resistant wicker range (as shown below). See http://www.dedon.de/