This is the fun and done method. You make your backing 2" larger than your front block so you have 1" all the way around when the front and batting is centered on the backing. The batting is is the same size as the block front.
Quilt your block before you sew them together. To sew the blocks together put the right sides of the backs together and using a zipper foot stitch close to the batting and the front block. Once this is done you will have two 1" pieces of backing sticking up toward the front. Lay the block flat and take one of the backing flaps and fold it with the raw edge next to the stitching (in other words, fold it in 1/2") then fold it again over the front. You'll have a 1/2" sashing on the one side of the block. Stitch close to the folded edge. Do the same on the other side. The end result is that you will have a 1" total sashing of the backing fabric showing between your blocks. Continue this across the row. Joins the rows together in the same fashion. Once all the squares are joined you will have a 1" of backing fabric showing all around the edge of your quilt. Use this for the binding. Fold in 1/2" and then fold over again and stitch close to the folded edge. You can miter the corners or fold them them at 90 degrees to complete.