“People often say that motivation doesn’t last. Well, neither does bathing – that’s why we recommend it daily.” ~ Zig Ziglar

Find inspiration, on a daily basis. Inspiration is one of the best motivators, and it can be found everywhere. Every day, seek inspiration, and it will help sustain motivation over the long term. Sources of inspiration can include: blogs, online success stories, forums, friends and family, magazines, books, quotes, music, photos, people you meet.
Get a coach or take a class. These will motivate you to at least show up, and to take action. It can be applied to any goal. This might be one of the more expensive ways of motivating yourself, but it works. And if you do some research, you might find some cheap classes in your area, or you might know a friend who will provide coaching or counseling for free.
Have powerful reasons. Write them down. Know your reasons. Give them some thought … and write them down. If you have loved ones, and you are doing it for them, that is more powerful than just doing it for self-interest. Doing it for yourself is good too, but you should do it for something that you REALLY REALLY want to happen, for really good reasons.
Become aware of your urges to quit, and be prepared for them. We all have urges to stop, but they are mostly unconscious. One of the most powerful things you can do is to start being more conscious of those urges. A good exercise is to go through the day with a little piece of paper and put a tally mark for each time you get an urge. It simply makes you aware of the urges. Then have a plan for when those urges hit, and plan for it beforehand, and write down your plan, because once those urges hit, you will not feel like coming up with a plan.
Make it a rule never to skip two days in a row. This rule takes into account our natural tendency to miss days now and then. We are not perfect. So, you missed one day … now the second day is upon you and you are feeling lazy … tell yourself NO! You will not miss two days in a row! Zen Habits says so! And just get started. You’ll thank yourself later.
Visualize your goal clearly, on a daily basis, for at least 5-10 minutes. Visualize your successful outcome in great detail. Close your eyes, and think about exactly how your successful outcome will look, will feel, will smell and taste and sound like. Where are you when you become successful? How do you look? What are you wearing? Form as clear a mental picture as possible. Now here’s the next key: do it every day. For at least a few minutes each day. This is the only way to keep that motivation going over a long period of time.
Keep a daily journal of your goal. If you are consistent about keeping a journal, it can be a great motivator. A journal should have not only what you did for the day, but your thoughts about how it went, how you felt, what mistakes you made, what you could do to improve. To be consistent about keeping a journal, do it right after you do your goal task each day. Make keeping a journal a sensory pleasure.
Create a friendly, mutually-supportive competition. We are all competitive in nature, at least a little. Some more than others. Take advantage of this part of our human nature by using it to fuel your goals. If you have a workout partner or goal buddy, you’ve got all you need for a friendly competition. See who can log more miles, or save more dollars, each week or month. See who can do more pushups or pullups. See who can lose the most weight or have the best abs or lose the most inches on their waist. Make sure the goals are weighted so that the competition is fairly equal. And mutually support each other in your goals.
Make a big public commitment. Be fully committed. This will do the trick every time. Create a blog and announce to the world that you are going to achieve a certain goal by a certain date. Commit yourself to the hilt
Always think positive. Squash all negative thoughts. Monitor your thoughts. Be aware of your self-talk. We all talk to ourselves, a lot, but we are not always aware of these thoughts. Start listening. If you hear negative thoughts, stop them, push them out, and replace them with positive thoughts. Positive thinking can be amazingly powerful.