I am not always happy but when I am these are some of the things that matter.
Definitely don't suffer fools unless you get paid a lot to do so.
Find a creative outlet, be it painting, drawing, writing, gardening, cooking or something else.
Keep on learning, hopefully things you are interested in.
Eat good food, especially local. It just tastes better. Right now I can't get enough local field tomatoes and corn.
Aim for sufficient financial security that you can buy the little things without strain. As an example, I am by no means wealthy but it makes me happy to be able to buy card making supplies without worrying.
Treasure family as much as you can. Life is short. Pass on those family traditions that make you feel good.
In your family, never go to bed with your anger. This is hard sometimes but makes a big difference.
Give yourself some slack. No one is perfect. So what if the laundry piles up for an extra day or too.
Be gentle with yourself. Really.
Give your children both roots and wings. Watching them become independent responsible (mostly) adults is amazing.