People who are optimistic, by definition feel happier now about the future as they assume things will be better than they likely will be, even in the face of a negative past.
Contented: People who are not bothered by the past or future can also just be happy in the present moment. Worry about the future is a common creator of unhappiness, and stopping worrying can give you a huge boost.
Achievement: People who challenge themselves, seeking to learn and achieve find pleasure not only in reaching their goals but also in the struggle and focus to get there.
They often set both smaller and larger goals, enabling them to get a sense of achievement in each of the little steps along the way to the greater joy of achieving something significant.
Caring: People who are altruistic, caring for others and spending time helping them often find great happiness in this. Caring for others gets you out of yourself and stops you worrying. Seeing others who are less fortunate than you can also have a contrastive motivation.
Integrity: Being true to yourself creates internal alignment and reduces inner conflict that prevents you from being truly happy. This helps to explain how caring works -- if you have an internal Values that says 'caring is right', then by caring for others you increase internal alignment.
Gratitude: People who are grateful for their lot in life and who show gratitude towards others for the things they receive have been found to be happier. Notably, thanks can be found in many religious prayers.
Humor: Those with a sense of fun and who can laugh, especially at themselves, are generally happier.
Laughing at yourself implies a sound sense of security with a reduced tendency to worry, which in turn contributes to happiness.
Activity: When people keep busy they are often happier than those who slow down, watch TV, surf the net and other less active things.
Activity reduces time for moping, adds interest and increases the chance of meeting others and finding happiness in new areas.