KATA 6-Inch Flush Cut Wire Cutters, Heavy Duty Side Cutter Pliers with Safety Cap, Sharp Snips for Crafting, Zip Ties, Floral Wire, Electrical, Jewelry, Chicken Wire, Artificial Flowers

Depends on your budget and patience and usual material really. I like snips because there's no mess. There's no metal dust, I can make coils and then cut them in my lap on the couch if I wanted to. Klein Diagonal Cutters should do you just fine for 18-14g mild steel or galvy, I've done 16g Stainless and 18g Titanium with them. Flush Cutters if you're on a budget and doing smaller stuff. The bigger snips won't be able to get in to small rings. When you're cutting your coils, do one ring at a time. If you're just starting and practicing hit the hardware store and buy some galvanized wire. You can get a spool of it for pretty cheap. It's not fine jewelry, you won't be wearing it on bare skin, and it'll make clothes/fingers stained black, but for the learning the mechanics of making/cutting coils, ring sizes and weaves it's easy, relatively strong, and cheap.