Root Can someone please explain backups?

I need to make a nandroid backup for my device before I start messing with Paranoid Android and Xprivacy in case I screw up and break my phone. Someone has said Safe strap, but I'm pretty confused about it. Some people say download a stock ROM for my device, others are saying make a backup, I just can't figure it out. I tried CWM, but it doesn't work on a RAZR running 4.1.2, and Safe strap is confusing me on their guide. I guess I'm not sure what I need to do.

Can someone please tell me exactly what I need to do to get my phone back in working order if I mess it up? There are a bunch of guides and all of them different, and I need a way to recover my phone if it goes south.