To stay on top of an action plan around weight, I am able to manage my eating, but think I will always have to do an exercise class, or just won't exercise in a consistent way. I haven't found any personal training that stuck, so am looking into Pilates.
I usually get derailed by family stuff. My husband doesn't like "healthy" food, like fruits/veggies, so I tend not to cook a lot of them.
For exercise, I find that sneaking in just a few minutes of stretches, doing a little extra house or yard work, etc keeps me moving. I've considered joining a gym, since I can get it free through my insurance supplement, but I figure there's no point. If I don't use the treadmill in my spare bedroom, it's unlikely I'm going to make use of a gym membership.
Because much of my weight issues are health related (thyroid, insulin resistance, etc) I find myself having a hard time staying motivated to keep up with a specific plan.
You know what else doesn't help? When your teenager brings home the large size Dean's French Onion Dip (in all caps) and a few bags of kettle chips. And they decide they don't like it. That's like putting crack in front of an addict.
Personally, I focus on small goals and surround myself with a supportive community for encouragement. Keeping a positive mindset and understanding that progress takes time helps me stay committed to the plan.