Ive seen alot of rolled fenders and when i look to see how my fender trimming is gonna go it looks like after im done it will trim out just as much as any fender roller will do.

 

I have not personally trimmed a fender... CBRD may be of some assistance, I think there is a thread about it somewhere.

Use tape and a rotating cutoff wheel has been one method.
Air saw is another method.
Snips seems difficult but you got the experience with them.

 

I strongly suggest reading this article by muellerized regarding rolling and trimming

http://www.socalevo.net/index.php?op...&topic=75624.0