Where in NSW. From the north you could start at the border and just keep going. There are so many huge beaches that you can have to yourself. Do you have a back up vehicle? 4wd? If you're after a pure semi remote sand run try Jerusalem creek to shark bay (between evans head and iluka) National park camping at the northern end and woody head camp ground at the southern end. No permit required to drive the whole way on the beach. If you have only a road car Pottsville to Brunswick heads/Byron is a massive run or south Ballina to Evans head. There's an endless list. Download google earth or check google maps and see the direction of the beaches and winds.