Pop in plants. Set in potted plants straight from the nursery to hide bare spots in the garden. The ferns in the foreground, for instance, are all new arrivals.
Set a green table. Make the garden feel lusher by bringing in other shades of green in furniture and accessories, as was done here with the bistro chairs, chartreuse tablecloth, and emerald minibar.
Steal from the indoors. Use your good china, glasses, and flatware. Fill some vases. Maybe even borrow an indoor rug for the evening. Make the table—and by extension the guests—the focal point.
Illuminate with footlights. Candles in clear vessels clustered in corners serve dual purposes. They make the space safer—no one tumbling over hedges or stumbling on stairs. But they also make it look more theatrical, and your guests will feel like stars.