Have sensible, achievable aims.  Be happy with what you’ve got, with what you are.  Envy and yearning won’t yield any happiness whatsoever so don’t bother.  Do the obvious things about mating, work and keeping healthy.

Almost all of the happy people around are married with kids.  I can’t prove that, it’s just my observation.  That doesn’t mean that there are no happy unmarried people.  Nor does it mean that marrying and having kids is a recipe for happiness.  It just means that settling down into a loving, caring family is a pretty good base for contentment.

Sex is important to happiness.  Married people have more sex than single people.  Your marriage prospects improve if you have a good job.  Your job prospects improve if you have a good education.  So, working reasonably hard at school really is a sensible route to future happiness.

Enjoy your work.  Note I didn’t say get a job you enjoy.  I firmly believe that any job is inherently enjoyable – all you have to do is work out what you have to do to do it well.  There is no such thing as menial work.  Work out what it is that your boss wants to be able to report to his boss – how can you make your boss look good.  Then go for it.  If it’s to do with keeping customers happy then talk to them, respond to their complaints, give them the best service they could have hoped for.  If it’s to do with producing high volumes of output or high quality standards work out how you can do that and talk to your colleagues about techniques.  If a job is boring it’s because you’ve allowed yourself to be boring.