While doing some research on the deck I’m going to build next summer, I ran across these Bolt-Rite anchor templates over at Awesome Tools. You can get ’em in a variety of sizes to suit your project/job. This 9″x9″ adjustable template takes anchor bolts up to 7/8″, and you can run conduit through the 2-1/8″ center hole.
Their aluminum construction makes them lightweight and reusable. You can adjust the templates for multiple applications. Center-line marks on the templates help with transit layout and stringlines. Normally $15 apiece, the price drops to $14 apiece when you buy a 10-pack.