i am just starting to figure these things out, thought i'd share~
do the things that make you happy and fulfilled as much as you can. everyone has their thing. for me its doing creative things like taking pictures or writing a song, but it could be as simple as riding your bike or dancing around your house. it can be easy to feel too lazy to do these things, and instead do something passive like look at pictures on fb, but if you try to spend SOME time each day doing the things you love it boosts happiness by so much!
if you are feeling confused, everything you need to know is probably already in your head. just do the things you know you need to do.
however hard it is, don't compare yourself to other people. it useless thought and will just make you either sad or patronizing. instead, focus on being the most awesome version of YOURself you can be...you will like yourself more and others will too!
be nice to others, even if you are in a bad mood or feel annoyed. putting that small effort to be nice (you dont have to pretend to be happy!) will lift all the mood around you and will probably make you a little happier too.
do some exercise! i've only recently discovered this. exercise can be fun, so do something you enjoy like maybe playing tennis or doing yoga or dancing or running...whatever but really focus on it and do it until your heart rate goes up and you sweat a bit. this kind of focus kind of like meditating because you forget about all those every day things and makes you feel so good and replenished.
it is not worth it to starve yourself! there are so many better things to think about than what you are/aren't eating all the time. and other people are much too concerned about how THEY look to care how you do. and if they are not thinking about that they won't care what you look like either!
work hard on the things that matter, and do the things that you do well. then after you work hard, your down time (or party time) is so much more fun and rewarding because you can feel like you deserve it!
spend time by yourself. i used to have such issues with being alone, but now i find it to be such valuable time. just a little walk with headphones on, when your mind can wander or reflect, and somehow my life and direction can seem so much more clear. this also really helps if you are feeling very emotional/confused.
this one is pinched from my bff ten's blog: "I always thought it's better to look at how you view the world instead of how the world views you." she is really wise!
i'm not sure if these will apply to everyone, and i don't like having an authoritative tone, but these thoughts help me realize it's not the end of the world all the time. and i don't mean to be a cheeseball, but knowing how to make yourself happy is really valuable! because being happy IS important. i might add more happy things to my blog as i think of them, cos why not?