This is an excerpt from the CNBC Make It newsletter. Subscribe here.

It's almost resolution season — aka the month I regret every decision I've made in the last six weeks, and vow to be nicer, healthier and more regimented.

My younger, more disciplined sister hates resolutions: "Why wait for a calendar date to do something that's good for you? Make the decision to be better now," she says, as I eat Christmas cookie dough and promise to give up sugar starting Jan. 1.

I wouldn't be a good older sister if I didn't find a flaw in her thinking: It turns out, resolving to eat less pasta and take more walks aren't really decisions at all, explains social psychologist Wendy Wood in her book, "Good Habits, Bad Habits."

After surveying hundreds of participants, she found one of the reasons we have a hard time forming healthier habits is that we assume implementing a new routine starts with a single, firm decision and is carried out by iron-clad self-will. This mindset is not only wrong, but unhelpful, Wood writes.

When we promise ourselves we're going to stop ordering sushi three times per week (just me?) and we fail to follow through, we beat ourselves up for not having self-control.

"The ethos is that your willpower is everything," Wood writes. "Self-change therefore becomes a kind of test of our personhood — or at least our conscious part."

Knock off the self-deprecation! We don't need to punish ourselves, Wood writes. We need to better understand how habits are formed. And learning about them is important: 43% of our daily actions are automatic, habitual behaviors, Wood says.

The key word in that sentence is automatic, meaning our habits rely on subconscious behavior. Wood frames it like this: You have to make the decision to ask your boss for a promotion. You don't have to think about kissing your child every day before leaving for work. You don't

That's why deciding to be healthier is hard. You have to decide (almost) every day to pick a salad over a burger. You have to decide every morning to get up, put on your tennis shoes and go for a jog, even if it's 9 degrees outside.

So, how do you implement healthier habits without thinking too hard? It's a combination of intentions and goals, rather than decision-making and self-torture, Wood writes.

Start small, she suggests. If you want to run a marathon with no previous experience, you're not going to simply jog 26.2 miles (or even 5 miles, in my case). So, get up and go for a walk. Gradually build up your endurance. Then, lacing up your shoes and hitting the track or treadmill won't feel like such a production. It'll slowly feel like second nature.

To be fair, my sister was mostly right. A fresh new year won't necessarily help you form new habits. But you need to be nice to yourself to begin. When it's hard to exercise or eat perfectly or if you just really, really crave takeout from a single-use plastic container, forgive yourself. Habits are built with goals and intentions, and not because you don't have the willpower.

For inspiration, here are some of the habits the Make It staff plans to pursue in the upcoming year:

• I want to lengthen my attention span and stop checking my phone so often. — Megan Sauer, associate success reporter
• I would like to start composting again. — Jessica Leibowitz, supervising producer
• I'd love to find ways to boost my energy without relying on caffeine. — Renee Onque, health and wellness reporter
• I want to safely get rid of the e-waste that has accumulated in my home. — Kathryn Mavrikakis, senior production manager
• I would love to cut down my coffee buying to only twice a week, and use a reusable cup when I do buy. — Marisa Forziati, video editor
• I'm hoping to up my step count to 10,000 steps per day (ideally by walking outside more). — Morgan Smith, work reporter
• I'd like to read more books! My goal is at least one a month. — Gili Malinsky, lead work reporter
• My goal next year is to exercise regularly and replace alcohol and sugar-y treats with seltzer, fruit and healthier options. — Jenna Goudreau, VP and managing editor

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