Don’t worry about the details; the less details your picture has, the better.
Use warm bright colors if you’d like to show happiness, and try to blend the
colors together getting new shades (oil pastels are amazing at blending).
Try to choose the main colors you will work with and blend them getting the
shades you want. Or, simply saying, have fun mixing different colors and
seeing the result!
Voila! You can see your happiness now! And you can quite literally show it to
everybody!