Don't be too concerned with what you've fallen short on. Enjoy writing your resolutions and see them as the necessary encouragement and inspiration you need to keep going. The important thing to remember is that every day that made up your 2012 has offered you a lesson with which to carve out your desires for 2013. Without the shortfalls and disappointments, you wouldn't have a healthy sense of direction now.
Another important thing to remember about writing resolutions is that they need to come from heart level. Don't pay any attention to what you feel others may expect of you or what you should be aiming to achieve. Resolutions only really work if you write them for you. No one else can tell you what to write on the piece of paper, so make it count. Think of the things you decide on as seeds which you're going to nurture so that they'll grow into strong, living things which stand the test of time.
Visualise your success. Use affirmations to help yourself realise your goals. Use creative expression to cope with the ups and downs of reaching the goals you've set. Repressing your emotional reactions to change, disappointment and success means that your resolutions are only living a half life as they become your reality. Be there with yourself all the way. Tell yourself you're going to make it real.