Do not neglect your back when you work out. I repeat, DO NOT NEGLECT YOUR BACK WHEN YOU WORK OUT. You back is the bridge, it supports your core which supports your entire body, therefore you need to strengthen it!
Most of us tend to workout without putting much thought to toning our backs but it’s extremely important. I learned this after a car accident where I hurt my lower back (which was already prone to being sore) and having to go to physical therapy. I slacked off once physical therapy was over and started ignoring my back again but got a swift kick in the butt once I later started working with a personal trainer. She was adamant about me doing supermans, which I absolutely hate but they’re worth it.
If you want to step it up a bit beyond the superman then get a stability ball (they sell them at places like Target for under $20) and put in that work. Here’s a demonstration from Chrissy K. Fit.