Decking is a great way to increase your living/entertainment space on unsightly level and sloping ground. There are various types of wood to use depending on the look you are after, such as kwilla, vitex and pine.
Exceeding the limit of permeable surface on your property is not an issue as water can drain through, allowing you to get creative with shape and size.
Screening serves many purposes in the garden. They delineate areas, create privacy and mask unattractive sights such as bins/utility. We love the idea of forming "rooms" in the garden to feel intimate, rather than a vast, open space.