Is a new year’s resolution any more than an aspirational notion? By the end of January will you still be working out four times a week, or will your runners be gathering dust under the bed as you scoff biscuits on the sofa?

This time last year I decided to take a different approach: to make or break a habit each month.

The deal was to stick to the resolution for just that month, then I could revert if I wanted. I was curious about how much of an impact little changes could really have, and a month felt like a realistic timeframe.

There was no formal plan – sometimes I chose the target or habit on the first day of the month. Nor did I record the minutiae of the outcomes. But I discovered a few surprising changes that made a big difference. Here’s how I got on.

January

Who ever has pots of cash in January? Not me, anyway. So it seemed a good month to avoid buying anything at all for myself. Did the January sales break my resolve? No. In fact, the only time I lapsed was a splurge on eyeliner during a momentary loss of attention.

My bank balance was still not terribly flush by January 31st, but I had become more aware of my shopping habits, and I have rowed back on buying stuff I don’t really need (like more eyeliner).

Tip: If you find you save a bit of money this month, try to donate what you can of it to charity.

February

Wine was in the crosshairs this month. It’s easy to fall into a pattern of unwinding with glass in hand after the end of a hard day, particularly if it is not a “school night”. So if the cork was calling, I found other ways to chill out: a cup of tea, a bath, a good film. By the time March rolled around and I took a sip of wine again, it tasted overwhelming.

March

While I was off the wine, a minor pastry habit made itself at home in my life and on my waistline. On the walk back from dropping the kids to school, I would call in to the local cafe for a hit of caffeine and an almond croissant – cold months can lure us into luxury. So March saw an abrupt end to this cushy calorie bomb, and the jeans quickly went on a lot easier. Top tip: if your regular path leads you into temptation, change the route you walk to avoid it.

April

I’m a night owl. On the stroke of midnight I get a surge of energy and enthusiasm for writing, which is great for meeting deadlines but perhaps not so great for health: studies are piling up that show a lack of good quality sleep is linked with increased risks of chronic conditions such as diabetes.

So for April I vowed to hit the pillow on the earlier side of midnight and, for the most part, I managed it. I have since drifted back to old ways when the workload requires it, but I am making an effort to close the laptop and the eyes at a respectable hour.

May

May was clear-out time. I made a concerted effort to sort clothes, toys, books and anything else that wasn’t nailed down into piles for friends and charity.

It was time consuming, but putting in the graft left rooms feeling airier, and it was gratifying to see items that were no longer of use to us enjoying a new lease of life with others.

June

This month I decided to do an “inverse pyramid” of squat exercises. Not as acrobatic as it sounds, it simply meant doing 10 squats for each date of the month. Starting on June 1st I dutifully did my 10, then 20 on the 2nd and so on until June 30th rolled around, when I did 300.

To stave off boredom as the month wore on, I watched Ted talks online while doing the squat sequences, but I made sure to keep an eye on form. My legs were now ready for the next challenge, which was . . .

July

. . . to run at least 100km in total this month. The timing was perfect: we were on holidays and I had time to do more running. It was tough, but spectacular views kept me entertained, as did audiobooks on my phone.

I racked up the kilometres listening to biographies of Jimmy Carter and comedian Michael McIntyre – an unusual pairing perhaps, but they saw me through the 100km barrier. I was delighted to see that when I tweeted about my plans, others took up the challenge too.

August

This month was about water: to drink more and to have a cold blast at the end of each shower. I took a bottle with me everywhere, sipped through the day and I soon saw and felt a positive difference in my skin.

The shower blast is a great way to wake yourself up, and I find that visualising jumping into the sea on holidays is a good way to endure it for 30 seconds. It’s an easy habit that I have kept up, but if you are pregnant or have any circulatory or other medical condition, please seek medical advice before trying it.

September

When I meet friends or do face-to-face interviews, I like to have a skinny cappuccino to hand. What would life be like without it? September was the time to find out. Where coffee was called for, I chose espresso or tea over frothy cappuccino.

After a while I didn’t miss the cappuccino and, once September had passed, I found myself no longer bothering as much to grab a coffee of any kind while out.

October

This month was something of an epiphany. I had been reading about mindfulness and meditation, and I decided to get down to brass tacks. Carving out 10-20 minutes each morning, I got stuck into the Headspace app (headspace.com) which guides you through basic techniques.

It wasn’t always easy, but I kept at it, and now I find if I don’t plug in for 10 minutes each morning, I miss it. During this year of living “monthfully”, getting going with this habit has probably had the most impact.

November

After the spectacular success of October, November was when the wheels fell off the wagon.

I tried to instil one habit after another, but nothing seemed to work. That said, it did show me how much I liked having a monthly project bubbling away.

And I started to think about the habits I had improved or kept – running longer distances, better sleep discipline, ditching pastries and getting some space of mind. Things weren’t so bad.

December

This month I have been starting the day with a smoothie blend of fruit, veg, water and occasionally nuts.

It’s more appetising than it sounds (adding half an avocado is a tasty trick) and, while the ingredients can be a little on the expensive side, it is a quick and easy breakfast.

Just as with the water, my skin is feeling the effects. And during the tumultuous party season, which can play havoc with good intentions, the smoothies at least deliver a daily dose of fruit and veg.

Tips for 2015 If you are keen to try monthly habits for 2015, here are a few tips:

Choose a single habit to make or break – it’s fine to have “accessory” goals too, but keep the main focus on one.

If you break your monthly resolution, don’t beat yourself up about it. This is an experiment, look on it as a bit of fun and just start again.

Be open to learning new things about yourself; you might be surprised at how small changes can translate into big benefits.