Put yourself on a schedule. It's what helped me... like at first I would say "Okay I'm gonna work out 3 days this week" and then each day I'd find an excuse to not work out and before you know it "Oh I only worked out one day last week... oops."

Now I have a schedule that I stick to. I workout when I get off work on Mondays, Tuesdays, Thursdays, and Fridays. So now I schedule things around my workout. One thing that really helped me too and is really important is getting enough sleep. Don't underestimate how much energy can be drained from you if you're not getting enough sleep at night. Also eating healthy and eating enough to keep up with your metabolism is important. Once you start seeing results you'll want to keep going with it too - that's how it was for me. Once I started seeing results I was really motivated to not only keep what I had, but improve on it as well.