Cutting sheet metal?

[SteveKG]

Those snips come in handy, I got both the right and left for about $25 each when I was roofing our cottage with standing seam steel panels. Since then, I've found them useful for a myriad of tasks. Take your time cutting if you are new at it. Wear some work gloves and you might have to "help" the piece you are cutting off now and then, keep it curling up and away from the snips [tug on it with one hand]. If you go slowly and carefully, you'll end up with clean and straight cut. Don't get junk snips; won't last through a couple feet of cutting without dulling.

 

[Battenkiller]

Make some practice cuts first, wide of the final mark.

Yes, not only will your cuts get better as you go, the waste side will curl away easier as it gets narrower and there will be less chance of introducing a kink or a twist to the metal.

Also, it is common practice to hit the corners of the cut edge with a sharp file to make a small chamfer. The edges will both look better and be much less likely to cause a cut if someone runs their hand along it. Only takes a couple of minutes and it gives a real finished look.