I went thru a new nibbler, which likes to eat material, then I tried various saws. We finally arrived at the (KISS) approach, a utility knife and a good straight edge held in place with vice grips will give a deep score, then a slight bend will snap a nice straight cut. We used this method for cutting 4" strips that were bent into floor channels.
We found that large snips do a great job for details.
David & Diana