Is it already in primary or are you planning this ahead? If you've already got this going, the auto-siphon is probably your best bet. If you haven't started yet, I'd advise using a fermentor with a spigot on the side so that you can transfer the clear liquid from the middle of your vessel straight through a tube into the secondary vessel. There is the option of passing that through a filter if you're concerned about debris, but you probably won't need that if everything's settled well and you're doing a secondary.