Have you considered shopping flea markets and yard sales for good used items? Sometimes you can find great things that simply need a good coat of paint. Consider using non-traditional items for tables or seating (ex: a huge planter can be painted, then a piece of stone, such as slate or a large metal tray can be placed on top for a table. Use an old small wooden crate as a seat by making a large flat pillow to place on top of it. Consider using an old clay planter to create a water feature (you would need to purchase a small pump and perhaps some water plants.)
Use items like painted window panes to hang as dividers for certain areas or simply as art.

Or if you're handy with power tools build your own bench style seating with planters and use lots of colorful pillows to make it inviting. Add large plants to help keep the area cool in the summer. Repurpose an old small dresser into a nice outdoor side table or bar by repainting and perhaps adding tile or mosaic to the top.