S: be Specific
Once you've chosen your resolution, write it down in specific terms and show it to a friend or your partner. Ask them how they would set about achieving this goal if it was theirs - and even more important, how they'd know they were making progress. Adjust as necessary.
M: set Measurable goals
Visible progress is extremely motivating, and the best way to see it is to use numbers. How many pounds is your ideal weight? How far do you hope to jog and in how many minutes? Notice I've suggested only positive goals. Measurable, positive aims are more motivating than vague, negative goals such as "be less of a couch potato."
Once you've defined your ultimate goal, break it into a realistic number of weekly sub-goals, so you can enjoy progress every week.
A: create Achievable goals
This is hard to do alone. Ask a good friend or a family member whether they think your aim is realistic, or whether instead it may stress you unduly and defeat you. Friends and family are likely to be kinder to you than you will be to yourself, as well as more realistic.
R: choose goals that are Relevant for you
It's too easy to feel pressure from friends, family or colleagues to set a target. But you'll never get there if your heart isn't really in it.
Try writing down the benefits you imagine if you achieve your aim. If you can't think of more than three, or if they're only about what others will think about you, choose a different resolution.
T: set realistic Time limits
After estimating how long you'll need, add 50 per cent to your estimate, or compare it to how long you would expect a friend to take. Work some slack time into your weekly steps as well, or allow for a "goal-free" week to make up for any lapses.
Finally, to make success even more likely, tell your friends what you're hoping to achieve.
Making your goal "public" will increase motivation. It also means you'll have people who can encourage you when you're feeling despondent.