Well it even goes beyond that.
Here are 4 Easy Tips to get you started.
1) Expressive Writing. Put your feelings down on paper. Your self-esteem will get a bump and your smile will get bigger.
2) Gratitude Journaling. There’s been a lot of this going around Facebook, and the web recently, and I think that it's for good reason. Spend 5 minutes daily listing the things you are most grateful for.
3) Recall those great moments from the past. Journal the times, moments from your life's past that are amazing.
4) Affectionate Writing. Now this one is win-win: Write to a person you love or care about and tell them how much they mean to you and why.
It may sound cheesy, but try it out for few weeks and let me know how it goes.