Even though I have a dremel and use it quite a bit, I would have thought "file" first just because it would look like a simple job for a round file, and it's certainly easier to be careful with a file.

I have a bunch of files, and even know a needle from a round from a three square and know what the card is for. 8-) But I was born in the early 50s and took shop class in junior high. Actually, I inherited most of them from my grandfather when I got his tools when he died. It seems I need to use my mill file every time I cut a carbon fiber steer tube just to even up my crappy cutting.