When it comes to making New Year’s resolutions, money resolutions –- save more, spend less, invest more for retirement – are right up there with eating and drinking less and exercising more for popularity.

But for actually achieving them, Jennifer Lane of Compass Planning Associates in Boston, who is also NECN’s "Ask Jennifer" expert, has some surprisingly low-key but powerful advice: "The first thing is to write it down." On a piece of paper or a Post-It Note, taped on a mirror or refrigerator or door where you’ll see it every day.

And don't just resolve to spend less and save more. Get specific. Lane recommends highly quantifiable goals like "'I’d like to put 1 percent more in my 401 (k)' or 'By the end February, I'd like to have another $500 in my savings.' If you write it down and put it somewhere where you'll see it, then you're much more likely to keep it on your radar screen and achieve it."

To save more, Lane stresses how valuable it is to really tally every dollar you’re now spending and identifying the spent cash that can become saved cash.

"People are often very surprised," Lane said, realizing that, for example, "I had no idea I was still paying for that monthly something-or-other subscription that I signed up for and I don't use. Or did you have any idea what you spent on lunch?" day in and day out over the course of a month and year.

I asked Lane what she would consider the number-one resolutions for people to make at the ages of 25, 35, 45, and 55.

"For age 25, it’s really credit and cash. You really want to build your credit by paying down your debt" and beginning to amass a cushion of savings. "Start it small. Make it an automatic direct deposit from your paycheck, $50, $20, $100, whatever fits for you."

At 35, Lane said, the top goal is a Roth IRA (non-taxed later) if you qualify or to "make sure you're doing your 401 k at least to the amount of your employer's match." At 45, Lane said, she would counsel people to "figure out how much you need to save for retirement and get that working. If you're not already maxing out your 401 (k), get the maximum into that account," which in 2015 can be a pre-tax $18,000 annually.

For 55-year-olds, Lane said the critical resolution becomes making sure that retirement account you’ve built up is properly balanced between stocks and bonds, offering both growth potential but protection against losing major chunks of what you’ve amassed. "A younger person can afford to lose money in the stock market and be very weighted into stocks. When you're 55 years old, you've really got to start learning about investments, making sure your portfolio is balanced," Lane said.

And whatever your goals around spending and saving are, making them specific, writing them down, and looking at them every day may well prove to be the key to determining whether they’re more than just good intentions.

With videographer Daniel J. Ferrigan and video editor Bob Leone