Hi there peps! its been a while...
Anyways, after studying some stuff, I learned one thing, really simple, that might be of help for lots of you :D
Ok, so its the writting test, dunno its name anymore but whatever, it goes like this:
Take a paper, a pencil and sit somewhere. then think about a topic... hmmmm, maybe your house? ok, your house, then write: My house is...
And then write everything nice about your house and everything good related to it! some people may say "Oh, but there isnt much stuff.." you will be surprised once you start writting paragraph after paragraph!.
But one more thing, it might not be really from the technique itself but I guess its worth trying.
After writting it down, you leave it somewhere where you can see it later, and next time you go to the place or go meet the person you wrote about, try seeing all its good points, ignore the bad, and then go back to your list and look at what you have wrote and add or just leave it as you like.
Its important to be enthusiasmatic about it, don't be sad if you can't think of anything at the start, it might happen that you are thinking too high! so take it from the bottom!
Example: My house is... Nice because it protects me from the cold rain and the snow, Its awnsome because it has plentty of space for me and my friends, and we have a big fridge to put loads of pizza! And so on and on...

Remember!: To work this out, you can't start thinking anything bad, its not helpful, instead, think about what might be its counter-part! like: "In the winter its cold" < "In the summer it is confy, because it is a little bit cold so I don't get to sweat all day".

The point of this technique is that as it is scientifically proven: Every though, if given enought force, can turn on a beacon for more thoughs on the same frequency(In other words, "like it"), so if you think good things, you will think about more good things, your mood will go up, you will be more happy and healthy!

Give it a try! I know you are reading this because you have pletty of free time! cmon! start it now!.

(P.S: you don't really need a piece of paper, just get something where you can transmit your thoughs to, but most likelly where you can write ;D)

This is a pretty neat idea to be honest. I have been trying to be more positive but it's a bit difficult if it's not something you're used to doing. Gonna try this for sure though, maybe I can condition myself.

Psych student here. Gonna correct your statement: it is impossible to scientifically 'prove' pretty much anything about states of mind. You can say the theory has a lot of support, but not proven.

You know, I might do the "Unhappy train of thought"

This reminds me of this teacher I once had. He said he hated tomatoes so decided to eat a tomato every day for a year. And now, he claimed, he loves tomatoes.
Sounds nice, right? But it wasn't. This teacher also displayed the fakest, most shallow happiness ever. It seemed so forced. My classmates and I soon learned from another teacher that he had a chemical imbalance in his brain so he forced himself to be happy so he wouldn't flip out and lose his job.

Not that I'm saying this is the same concept. The OP's idea seems like it would actually work. I also like NZPIEFACE's idea; doing both at the same time would be cool. And what you write down might even parallel each other. Sure, the floorboards of your house are always creaky, but they're loose enough for you to lift up and hide stuff underneath. The ceilings might have stains on them and it's embarrassing for your friends to see, but when you're bored you can pass the time by making shapes out of them....and so on.