Bodork, I am NOT an expert...but I got a piece of cheap strap steel from HD and practiced on it..i found that if you 'angle' the file rather than hold it perpendicular to the blade your design tends to get more fluid, or organic looking rather than mechanical.
You might try that and see if you like it. Its not hard, but I would definitely practice some at that technique before I used a good blade doing it.
Thats the voice of experience talking there. You can have experience even if you are not an expert, and its usually bad experience...but at least you are learning when you do!!!!!!!