1. Great Expectations: Be realistic with yourself when setting fitness goals. Where are you right now and where do you want to be? Going from zero to 60 isn't safe, and an over-challenging goal is just as un-motivating as one that is clearly too easy. As well, seeing healthy results takes time, so don't throw your hands up after a month when you haven't got a Victoria's Secret contract.
2. Make it so: We are all busy and therefore we can all find some excuse as to why exercise isn't a priority. Make it a priority. Find a time of day/time of week that works best for you and treat it like an appointment that you wouldn't miss. Being active makes you more productive at all of your other activities, including getting good sleep.
3. Are you not entertained: It makes sense that if we hate something, we're going to go to great lengths to avoid it. So pick something you like to do to increase your chances of sticking with it. That's not to say you shouldn't feel the burn or be a little stiff the next day, but those things should give you a sense of pride not a sense of dread.
4. You've got a friend in me: Grabbing a buddy and getting active together increases your sense of accountability to the activity. In other words, you don't want to be "that guy" who ditches hot yoga when you've made a date with a friend to go. Or, arrive a little early to a class you're taking and make a new friend who clearly shares one of your interests!
5. Measure up: Find some way to measure your progress to see how far you've come and pat yourself on the back. Try to look at alternative measures than weight. How do you feel? Are you happier, stronger, less tired, eating better? Seeing where you've come from increases your motivation to set more goals!
These are all common sense, but sometimes you just need to bring it back to basics to get going again; Happy exercising!