Wedding staging simply means you create areas of "interest" that creates photo ops and backdrops for photographs. Outdoor wedding can be really fun, since you can create interesting backdrops with items that create the spirit of your wedding theme.
If your theme is casual, check out thrift stores for interesting props, such as stools, small tables, large vases, crates and other items that can be used as stands or tables. A wide selection of decorative sprays can change the colors. Beautiful muslin or jute ribbon can be wrapped and tied as bows.