I'm sorry, I don't have your three things. It's my warped sense of humor - I am a sucker for lists of tips, reading them is like eating something sweet and salty with no calories. I don't really think there are three activities or strokes of luck that would suffice to make anyone happy. Less neurotic and less miserable, yes, generally satisfied with life, yes, able to be happy, yes. But those are things that take dedicated effort over a long time---for instance, a daily spiritual practice and getting enough exercise and saving for retirement---and do not bring instant gratification. There, that's three - but nobody is interested in tips like that. Tips are about Instant! Free! Easy!!
Here's a suggestion, though. Start a list of things that make you feel better. Here are two I experienced this morning:
1. Getting a handle on tonight's dinner first thing in the morning. I actually got chili going in the slow-cooker, no small feat working with single non-dominant hand. It smells good, I feel proud, I'm looking forward to dinner. If you are your own or your family's main cook, what to have for dinner will be lurking on your mind all day long unless you decide in the morning what to have. Truth is, I learned this from a site called The Fly Lady. If you need someone to nag you to do what has to be done around your house, go there.
2. Getting three! comments on this blog, and from new people. This is the obverse side of my personal problem, which is that I hate my writing to be rejected. On the other hand, I love for someone to tell me it matters to them. New readers make me happy, too.
Your list will be different. Be careful about putting on it things that society has told you ought to make you feel better, I don't know, massage for example is torture to me. Stretching, however, is great. I loved yoga (with a great teacher, whose name is Kit Spahr if you live in the Columbus area) back when I could do it. Hate running. Love Ghiradelli chocolate with sea salt and almonds - it actually lifts my mood. Love soft socks, supportive shoes. Hate getting a manicure, but enjoy wearing the right nail polish. See, this is very personal.
The list of things that make me feel better is actually a sort of spiritual/psychological exercise that I made up for myself a long time ago. It is a way of paying attention to yourself.
Now I have to go take my noontime immunosuppressants. I have to do this every day of my life now, and I don't mind it, it keeps me alive, but it doesn't make me feel better. No pushing the list by putting on things you ought to be grateful for - that's a different exercise.