1) Plan - no matter what you set out to acheive, there's absolutely no way in hell that you will have long-term success without planning. And I'm not talking, "okay, I'm going to go to the gym this week" type of planning. I'm talking "I'm going to the gym right after work M-F" and then scheduling it in whatever you use for a scheduler (I prefer Google Calendar).
2) Partner with a Like Minded Friend / Community - thinking about skipping your workout? That's okay because you won't since you told your friend that you would meet them at the gym at 530 tonight. This is powerful stuff. Use the power of your network/social circle and if you don't have anyone, then there are plenty of communities out there that you can join where you will get the support needed to help you reach your goals.
3) Reflection - back in late 2012 I ballooned up to 204 lbs. It was the heaviest I had ever been (if you've seen me over the past 3 years, I have walked around between 178-184 lbs).
I had immersed myself in work and a dysfunctional relationship at the time and lost sight of how I was treating my body. The first time that I realized how negligent I had been is when I played basketball for the first time that Fall. I was in horrible shape and things that I could do before with a basketball my body was not able to do. It was beyond frustrating, but it was the first reality check I had.
About a month after that I got the flu on New Years Eve. I was sidelined for the next 3 days. During that time I was forced to reflect and realized "I need to get my shit together. I haven't been honest with myself on how I was eating."
Don't do what I did and kid yourself that you're doing your best or even that you're doing a good job. Because I wasn't even close.
Don't do what I did and wait for something painful to happen that forces you to reflect.
Make it at bare minimum a weekly practice.
4) Hire a Professional - commit to the general practice of whatever you're trying to achieve, and then hire a coach that can save you a lot of grief, money, time, and energy.
For example, if you have decided that you're going to commit to pouring more money into your retirement, then it's probably a good idea to hire a Certified Financial Planner rather than tackle it on your own.
Personally, I've hired a ton of professionals to help me with everything from financial planning to business development. To me at this point, whenever I seek to achieve something, I hire a coach.
If you're struggling with your fitness, then I highly encourage you to check out my upcoming "8 Week Transform & Perform Program" by clicking here. Get on the Insiders List and get $150 off! We start up February 1st!