What’s the best way to tackle problems that arise on your way to success? First, remember no matter how well you plan, change is hard. “You’re up against a part of yourself that’s never going to change. It’s always going to push at you in certain directions that are unhealthy. You’re going to have to really create something step by step in order to manage it,” Dr. Bennett said.

So before hurdles get in your way, make sure you have a plan to jump over them. Here are a few common problems people face in achieving their goals:

It’s too much and I have so far to go. A perceived lack of progress can be frustrating. Dr. Wallin suggested focusing on whatever the smaller number it is: your progress, or how much you have left to do.

This “small number” technique is based on a 2012 study published in The Journal of Consumer Research that found that focusing on the smaller number in reaching a goal kept people more motivated. So, for example, if you want to run five miles, which of the following thoughts is more likely to keep you going?

I’ve already run one mile and in another mile I’ll double it

I’ve run just one mile and I still have four more to go

According to this theory, you’re likely better off with the first one.

So when you are first starting on your journey toward your resolution, instead of looking at the big number left to get there, look at what you’ve already achieved. Toward the end when that goal number shrinks, it’s perfectly fine to look at your progress, but zero in on what little remains before you hit your goal.

I’m trying to stay positive, but it’s not working. Positive thinking isn’t going to be enough, said Gabriele Oettingen , a professor of psychology at New York University and author of “Rethinking Positive Thinking: Inside the New Science of Motivation.” In fact, positive thinking may be the thing holding you back.

In her studies, she’s found that “the more positively people fantasize and daydream about their future success, the less well they do in terms of having actual success,” she said.

“They already experienced it positively in their minds, and then they relax,” she said. “These positive fantasies are helpful for exploring the different possibility for the future, but they are a hardship when it comes to actually putting in the effort and the energy that wish fulfillment actually needs. They sap energy.”

A better technique than positive thinking? Try to be positive, but realistic. Yes, imagine the goal or positive fantasy, but then look at what obstacles are in the way and how to get over them. Dr. Oettingen calls this technique W.O.O.P. — Wish, Outcome, Obstacle, Plan.

Wish: What do you want?

What do you want? Outcome: What would the ideal outcome be? What will your life look like when you hit your goal?

What would the ideal outcome be? What will your life look like when you hit your goal? Obstacle: You know yourself. What will try to stop you? What has sidelined you before?

You know yourself. What will try to stop you? What has sidelined you before? Plan: How will you get around it?

Answering these questions doesn’t need to take a lot of time. Dr. Oettingen suggested three to five minutes to start; make sure you’re in a place where you won’t be interrupted. (Want to try it? Here’s an app that might be useful. )

I can’t stick to this routine. Maybe your routine simply isn’t flexible enough.