Try a square bladed edging spade, if you've been using a half moon. It is quicker and cleaner.
Another huge time saver is to drop a big piece of sod over an area that you need a small piece in, then cut a bigger shape around it going through both layers of sod. remove the pieces you cut from the bottom layer and press the top layer in its place as a perfect fit. This also keeps the edge pieces bigger so they don't dry out or get sucked up by a lawn mower.