The key to being successful on any fitness plan is to exceed minimum daily actions (MDA's) set around things you can control, tie those into weekly goals, then collect and evaluate information on a regular basis. That's the Your Level Fitness Framework.
The hardest part about getting in shape is the headspace. The default thought process most people have around exercising more and eating better, is they have to go from doing very little up till now, to a regiment that's so specific & challenging it would make an Olympic athlete blush. Unless you're able to fit your life around a program "flipping the switch on" won't work. That's where minimum daily actions (MDA's) come in.
Minimum Daily Actions
MDA's take what you think you're capable of doing now and scale it back to something that seems so embarrassingly easy, you'd feel sheepish telling someone you couldn't go beyond it. In practice, these daily actions would look something like this:
Exercise for at least 15 minutes
Drink at least 48 ounces of water
Eat at least three servings of produce
If these look too easy for you - that's the idea :) If not? scale them back further. Make your actions so specific you can look at them and answer how you're doing with them with a "yes" or "no". Once you have the actions down, it's time to tie them to weekly goals.
Weekly Goals
Even though MDA's are setup to be easy to exceed, there's still going to be times where you can't hit them. That's why setting weekly goals with enough wiggle room is so important. Just commit to hitting each MDA goal at least a certain number of times per week.
Four is a great number, it gives plenty of slack and you'll start thinking of yourself as the fitness dynamo you are after exceeding your weekly goals every week for a couple months. What happens if you're not exceeding your goals? That's right! Scale them back a bit. Now, exceeding goals is great, but you want results. Let's talk about how to make sure you're getting those.
Progress Updates
Every two or four weeks "you decide which" take a waist measurement, progress photos and get on the scale. Do all three so that one isn't being seen as more important than the others. Here's the "why" for each:
Waist Measurement: This is where most people carry their extra weight. If yours is elsewhere, measure that area instead.
Progress Photos: Take a front, side and back view picture, in your workout clothes.
Get on the Scale: Many people have a complex relationship with the scale. I believe that with this framework you can improve your relationship with the scale because it’s one of multiple pieces of info collected as part of progress updates, instead of being the main focus of the updates.
Jot down and keep this info. After 3-4 progress sessions you should have enough information to tell how well you're doing on your program. Evaluate those results and adjust where necessary.