1. NEGATIVE VISUALIZATION.
What's the worst that could happen? Put things in perspective - most likely you are over-dramatizing.
2.THE "AS IF" THEORY.
If you want to achieve a quality, act as if you already achieved that. "Smile and the world smiles with you!"
3. MAKE IT A TREAT
If you deny yourself a luxury once in a while, you stop taking it for granted and feel more happiness over it when you finally GET it! (Also boosts your self control!)
4. LIVE IN THE PRESENT.
Stop worrying about things that are out of your control (such as past memories and future fears) and start noticing the things around you NOW - take joy from what you CAN change. It's a much better use of your attention and energy.
5. IT'S OK TO STUMBLE.
Self-criticism is correalated to low motivation and low self control. On the other hand, self compassion makes us able to learn from our mistakes and helps us understand that nobody is immune to failure. Forgive yourself and move on - you will be a happier person for it.