I would say that reality creation is not mostly about feeling better, but all about feeling better. :)
You could actually do nothing whatsoever in your life except feel good and everything you want would flow to you easily and naturally. That's basically the way I do it with my manifesting spreadsheet...just ever-growing lists of great feeling thoughts.
I haven't actually used the box approach (Manifesting Experiment 1) for a few years though it is very effective as well (so don't give up yet!) and I've started using it again now just to experience the experiment from the point of view of those taking part.
I know these two approaches can seem completely contradictory and confusing - one says you'll get whatever you want by just feeling good and thinking about nothing you want, while the other says you have to get very clear about what you want and just not feel anything much at all after that (i.e. forget about it).
So let me try and clear up that confusion for people - it took me quite a while (and a large dose of Abraham) to really understand why the two apparent opposites result in the same outcome (of getting what you want).
The key point is that when you desire something, a broader (non-physical) part of you vibrationally becomes that thing.
So, for example, if you desire a new car, the broader (non-physical) part of you now becomes the vibration of you with the new car.
Notice this point carefully. You are not creating a new car because the new car was created (vibrationally) in the moment that you suddenly made a decision to want it (Step 1).
You are simply aligning with the brief vibrational glimpse you had of the new car when you launched your rocket of desire for it. During that brief glimpse, you left your broader you up there with the new car, which is why it now feels uncomfortable that you don't have it...there is a vibrational gulf between you and the broader you. This explains why it is more painful to have a desire and then try to ignore it, than not having the desire in the first place.
Everything you do to get that new car from now on is actually Step 3. And the reason that you have to feel better to get the new car is because in feeling better, you are aligning yourself with the broader you that is already living in a vibrational reality with the new car. That broader you is effectively pointing the way (through emotion) for the physical you to go.
In other words, aligning yourself with the broader you is the same as aligning yourself with what you want.
And since the broader you has similarly expanded to become the vibration of everything else you want in life, then just aligning yourself with the broader you is also the same as aligning yourself with everything else you want. (Feeling good simply means you are in alignment with the broader you).
This is why just feeling good brings you everything you want...because the broader you and everything you want are all in the same vibrational place.
But then why does getting very clear about something you want, and then releasing it, also work?
This is because, as hinted at earlier, getting clear about something you want is not creating it (Step 1) but is actually coming into alignment with it (Step 3).
When you think about something clearly enough that you are in vibrational harmony with it and then you immediately step out of the way of it (by forgetting it), it must manifest into your physical reality because you are not holding any opposing vibration...and your vibration on any topic always stays where you last left it.
When you realize that focusing like this is really a Step 3 process, not Step 1, it starts to become apparent why it is not necessary to spend hours using Creative Visualization, Affirmations, Goal Focusing or whatever, to get what you want because you are not creating anything with those processes. The thing you want was already created in the moment of wanting it.
The people that advocate action to get what you want are misunderstanding what the action does. Taking action with the belief that taking that action will get you what you want is actually an alignment process (Step 3), not a creation process.
So, in fact, you could actually take a small amount of action just to make yourself feel good (like putting some paper into a box) and do nothing else, and you would create the same result as taking massive amounts of action.
That's basically Reality Creation in a nutshell...though I appreciate it might take a few readings of this posting to really understand what I'm yapping on about. I hope this isn't all too confusing :)