Set a goal: Saying "I want to better my personal life" is easy, but the first step to actually making it happen is to imagine it. Get your pen and paper and write a few ideas until you find one you're happy to focus on. It should be something specific and measurable. If, for example, you wanted to lose weight, you would set a target weight and then make sure that you had a scale to weigh yourself.
Brainstorm how to achieve your goal. Continuing with the weight loss example, you could take up running, weightlifting, start a diet, or do all of them. Cast things in a positive light: Rather than obsess about what you are giving up, think of the changes you are making as positive steps: for example, think about eating more fruits and vegetables as eating healthier rather than as a punishment.
Break down the methods you're going to use. For example, if you are going to diet, think about how you can change your eating habits. Do you need to research diets? Do you need to get rid of tempting food in the pantry? How will you monitor what you eat and how much? Write it all down so that it's always obvious what you need to do next.
Tell people about your mission to better your personal life. If friends and family know about it, you are more likely to stick with it because people who care about you want you to succeed. A friend or family member also might want to join you, which makes it even easier to stay the course.
Start making it happen. If weight loss is your goal, you would find a diet you are happy with, buy a scale, get a gym membership, and tell friends and family what you intend to do. Go through your list of steps that need to be taken and start taking them.