Do you mean 'happy" or less sad/neutral? I'd be interested to see what steps you take to achieve that. I don't expect happiness every day (all though it sounds nice).
Well, it's nearly impossible to be happy all the time unless you have mania or another brain disorder.
But, several things dictate your emotional state - happiness, sadness, neutrality, anger, etc. All of those feelings are not inherently felt by anybody (thought they often seem like they are), and they're not actually felt until your body (brain-body relationship) creates them.
Your overall body composition goes into your initial feeling (physiology which I learned from our beloved Light), as well as your:
-Mental Focus
-Language
-Physiology
-Story You Tell
I'm trying to keep things coherent and not ramble on and on about this because I could explain so much more, but I'll give a brief write-up on each of these - and if you want to learn more I'll be happy to explain away.
*Mental Focus/Story You Tell - Think about this situation. You're up late into the night, it's 1 A.M. and your girlfriend isn't back yet. She left for a while, said she was going to a party with some friends and would be back around 11... The story (how you choose to explain the situation) affects your emotions.
If you think she's cheating on you - you'll react one way.
If you think she got caught up with friends and forgot about the time - you'll react another.
If you think she was on her way back and got into an accident - you'll react another.
and it's your choice to change the story - just ask yourself what else could the situation mean?
Language - This is part of something that Anthony Robbins calls the Triad (language, mental focus, state/physiology) and the Language portion of it is what you say to yourself to explain something.
People have patterns of Language as well - for some people, certain words just automatically put you in a certain mood (whether it's good or bad).
How you say things to yourself is important as well - do you use curse words, is your tone of voice angry or hostile, is it warm and sweet?
All of these sections of Language affect your emotional state as well.
Physiology - Again, I learned this from my good friend Light =P I'm not going to steal his thunder either - he did a nice write up on the power of physiology for overcoming approach anxiety.
But, your physiology can be used to create any mood you want, not just the ones he mentions.
You can find Light's write up
here
Again, if you need extra explanation, or have any more questions, feel free to respond
-Richard