I dont know how to achieve true happiness but one way I am sure you wont; analyzing life endlessly on the internet. Seriously. The less I think (about life, issues, happiness, blah) the happier I am. Those are just pure teories, lists. Isnt it silly to actually make A LIST for "how to be happy"?! You can go out of the house and be dead next minute. You sure wont be proud that you were making some nerdy lists a minute before that... that have no contact whatsoever with real life.
I think thats one way to be unhappy - analyzing things over and over again. With all different things around you, beauty, to analyze what will make you potentially theorethically happy - wow, talking about neurosis!
Smile. Breathe. And dont take things too seriously. Thats what contributes more to my feeling of happiness than anything "greater"; and i always expected that some sense of "meaning" will make me feel happy, but actually its the opposite... I dont care about meaning (thats too heavy word imo) when i feel happy. No need for greater things, when i feel happy - maybe happiness means enjoying things without always wanting more.