I agree with chain saw files in all sizes up to 1/4". I have a set of needle files but do not use them much. If you plan on doing a lot of rope or vine patterns, get yourself a fine small flat file (1/2" wide x 1/16" thick) Grind a 20ish degree bevel on both edges from the same side. This will give you a fine cutting edge with a safe side. If your staight cut is too far to one side, flip to the other edge and you can true up your cut. When you have broken too many teeth for a smooth cut, regrind the file.
Hope I have not confused you, it is much easier to do than explain. Give it a go, every one I have shown this to has adopted it.