I use the Lansky Deluxe Diamond Sharpening System and a leather strop. The jig helps prevent mistakes such as rounding off the point. You can often find them on sale and they work well; mine has been going strong for almost a decade. It's not the most high end sharpening system out there but it achieves a near perfect mirror finish on the edge.

There's lots of similar sharpening systems and if you've got the cash you can get some really beautifully designed jigs. Although people who are experienced with whetstones can certainly achieve the same (if not better) results.... it just takes a lot more practice.