Terrible Ones?

So I've heard about the terrible twos but I honestly think it starts early. My LO just turned one and let me tell you I don't know where this temper comes from! Since I'm a FTM just wondering what you do to stop a tantrum. I've heard just ignore them (which is a bad idea. My little one throws herself back and I don't want her banging her head) I've tried redirecting her attention and when that doesn't work I literally have to set her in her crib till she falls asleep from the screaming. Am I doing anything wrong? I don't want her to learn that if she does that she's going to get her way. Just don't know what to do and it seems to be happening more. Any advice?