Rib Edge Finishing
I don't think there is a "best" way, only the one that works for you. I would suggest deburring the ribs before you flute them (not an insult, I did a few of mine after fluting). I use a variety of methods, most in combination, including:
-a V edge deburring bit that gets both sides in one pass. Use this lightly and make several passes, it's very easy to "chatter" the tool and the marks take a long time to get out.
-a single blade deburring bit that can be used on small features such as flange bending reliefs
-files including a 4" and a 10", various cuts
-a 6" scotchbrite wheel on a grinder. This gets a number of grooves worn in it over time and these can be used to guide the edge as well as deburr both sides of the edge. On most ribs, the flanged edges can be deburred with this wheel
-a 2" and a 1" scotchbrite wheel usually on an air drill, sometimes on the drill press. These are especially handy on lightening holes.
-a Cratex 777 wheel kit and a dremel tool for really fine work
http://www.cratex.com/rubkits.htm
But it is still a lot of work to get good smooth deburred edges on sheet metal parts!