One of the best tips I heard recently about keeping a resolution was to commit to it until Valentine's Day. Seems like a reasonable time frame, and gives me a goal to reach for. The other tip was to be very specific and realistic about that resolution. It's not enough to say, " I'm going to exercise more" or " I will lose 20 lbs. by spring". Set a smaller goal for weight loss and be specific about how many days per week to exercise. As a lifelong exerciser, my way of keeping myself on track is to keep an exercise calendar. After every workout, I write it down. Towards the end of the week, I can see if I need to throw in an extra cardio or yoga day in. I keep the calendar somewhere visible so I can't ignore it :). Life happens, so cut yourself a break if you falter once in a while on that resolution.
Happy New Year!