You’ve decided to make some positive changes in your life. That’s a good first step. Now get started!

“It’s never convenient to change ingrown habits, so now is as good a time as any,” says Pauline Wallin, PhD, a private-practice psychologist in Camp Hill, Pa., and member of the American Psychological Association.

No one says it’s going to be easy to make those changes, but here are some rules of thumb.

Commit yourself to the task

Before you join a gym or change your job, decide you’re ready to do the work it takes to make such a change—and do it for yourself. You’ll be less likely to succeed if you’re setting goals just to please your family or because it’s fashionable. “If you’re prepared to accept the responsibility and discipline, you’ll be more able to sustain your motivation,” Dr. Wallin says. Then make your goals a priority.

Choose reasonable goals

Write them down, focusing on just one or two specific goals. And make them realistic, says Alan Marlatt, PhD, professor of psychology at the University of Washington in Seattle. “If you insist on ‘all’ or ‘none,’ ‘never’ or ‘always,’ you may set yourself up for failure.” Frame your goals in the positive. Instead of “I will stop eating sweets,” say, “I will improve my eating habits.” Then break your goals down into smaller, more manageable ones. “People who make gradual changes do better,” he adds.

Reinforce your goals

List the three main reasons you want to spend more time with family, for instance. Look at your list regularly to remind yourself why your sometimes difficult journey to change is worth the effort. Every day, say your goals out loud so you can hear them, and “feed” yourself positive self-talk and affirmations. And be patient. Any meaningful change takes time.

Seek support

Maybe you’re reluctant to share your goals with others for fear of embarrassment if you fail. “But telling friends, family and/or coworkers bolsters your goals and gives you external motivation,” says Dr. Marlatt. Use the buddy system. If you know others who also want to improve their physiques, for example, arrange to meet at the gym. Socialize with people who inspire you to practice good habits.

Plan your strategy

It’s not enough to say that you want to save more money. Decide exactly how much you’d like to have put aside by a certain date. Then figure out what percentage of your paycheck you’ll deposit in the bank each month. Plan specifically how you’ll respond to temptations. Decide in advance that if you buy shoes instead of making that deposit, you’ll skip a movie with the girls for a couple of weeks.

Monitor yourself

A timetable that lays out concrete results can help you measure your progress. Keep a diary of your achievements and challenges, and your feelings about them. “Be observational, not judgmental,” Dr. Marlatt says. “You’ll begin to see a pattern of what works and what doesn’t, so you’ll know how you can improve your actions and/or modify your goals.”

Expect setbacks

“With any new learning experience, most people make mistakes,” Dr. Marlatt says. “In general, it takes about 90 days to make a significant change in behavior.” Focus on the positive and learn from setbacks, adds Saundra Gilfillan, DO, clinical associate professor of psychiatry at the University of Texas Southwestern Medical School in Dallas. “Don’t view partially met goals as a failure,” she says.

Take credit for yourself

Acknowledge your accomplishments along the way to your goals, and praise yourself for progress as you go. Says Dr. Gilfillan, “Why wait for the end point of what you planned for the goal? That may take a while.” Each day you haven’t had any beer or wine, for example, drop a dollar bill in a jar and you’ll have saved enough for a relaxing day at a spa.

While you strive to fulfill your goals, “be reasonable and good to yourself,” Dr. Gilfillan stresses. “Appreciate all good choices that lead to an improved sense of self, whether your goals are met completely or only partially. As long as you stay focused and determined, and continue to work on your goals, that is success.”