It's the start of the New Year, and that means consumers are making resolutions—again. The top three financial promises that appear year after year, according to research from Fidelity Investments, include: saving more money, paying off debt and spending less.

As resolutions go, many are often broken. Still, Fidelity says of those who made a financial resolution last year, more than half say they are better off financially.

Read MoreHoliday spending shifts away from 'stuff': Pro

Even better news: an overwhelming majority of those who set out to improve their finances at the start of the last New Year realized at least half of their goals, while nearly a third achieved their financial goals completely.

Financial resolutions are no easy feat, but they are manageable. Here are four to keep in mind, not just in 2015 but throughout the arc of your life.

One of the most important things you can do is to keep track of your spending. You cannot save money if you don't know where your money is going. Financial apps like Mint.com are free and help track your spending and offers many charts to show you exactly where your money is going.

Review your essential and discretionary monthly expenses. Determine whether it makes sense for you to cut costs, pay down debt, or save more. Start by taking these small steps, which everyone should be able to do.

Create a budget and stick to it throughout the year. Doing so can help you find more money to save.

Read MoreWhy more American families are going cashless

If you haven't already done so, start building a liquid emergency fund. Ideally, you'll need six months' salary to cover expenses in a pinch. But you can begin small, mainly by saving loose change: By just putting aside 50 cents a day, over the course of a year you can save more than 36 percent of a $500 emergency fund.

Most people may think it's not worth it to put aside 2 quarters a day, but the reality is that many people can do so—and the numbers show that it adds up over time.

The challenge that most consumers find toughest is one that can be conquered with a few small steps. The first is reviewing your credit card bills.

Many people are accustomed to charging their credit cards, but many don't actually sit down to review important information. If you do, you will realize the account that is doing you the most damage is the one with the highest interest rate.

Start there and pay the most expensive balance first. Borrowing money for things you can't afford (or don't really need) usually gets you into trouble over the long term, because the interest rates you pay every month on credit cards can often derail your efforts to save money.

Read MoreBig changes are coming for credit cards

Call your credit card provider and ask for a lower interest rate. If you're a good consumer and have made timely payments, they may be willing to lower it for you.

If you're considering doing a balance transfer, you should first get out your calculator. There are fees associated with transfers, so you want to make sure the lower interest rate offsets the fees. Many credit cards in the New Year offer zero percent interest rates for a limited amount of time.

You can be a savvy consumer and make that work for you if you're very disciplined. That means you'll need to fight the temptation to use that newly cleared card, while also committing to paying off the balance you moved over in a timely manner

Retirement is not what it used to be. Luckily, however, in the New Year you can save more for retirement on a tax-deferred basis.

The limit on 401(k) contributions has increased by $500 to $18,000, from $17,500. Review your benefits to see if you're taking advantage of your company's match program.

If you're 50 and older, you can take advantage of the "catch up" contribution, which has also increased to $6,000 from $5,500. According to the Plan Sponsor Council of America, 97 percent of all 401(k) plans permit catch-up contributions.

Contribute to, or open up, an individual retirement account (IRA). Many tax-planning strategies end when the new year begins, but that's not the case with these accounts. You can open a Roth IRA or a traditional IRA, or contribute to an existing one, until April 15.

That way, you potentially reduce your taxable income, dollar for dollar, subject to phaseouts based on income.