Your market is a really cool idea ! This is the first time I’ve been really interested by a prediction market 
I don’t have a Manifold account, so I’ll give you a suggestion here.
With my own experience in the pursuit of happiness (journaling here), I noticed that I am not so good at predicting what would make me happy, but very good at predicting what is making me sad.
From what I understood, you have some of these thoughts popping up: “I am doing video games, but I wish I worked” and “I wish I socialized more”.
Maximizing happiness might be more about finding these “I don’t feel good because X” and fixing them rather than doing “feel good actions”, like doing more pushups.
(I think the philosopher who talks about this is Epictetus, but I never read it, so I might be really wrong 
)
So, my idea #1 would be to build a framework around the idea of minimizing pain; with discovery of what’s actually holding you back from happiness at the forefront.
- Discover what makes you unhappy
- Fix it really well
- Done
Rather than
- Find something that might make you happy (pushups?)
- Do it
- Maybe it worked ?
this strategy is interesting for the last 20% of happiness-getting, but maybe not so much for the first 80%!
So here is my official submission to the idea list: “making a Beeminder goal to journal everyday about what made you unhappy today, on pen and paper — and what you could do about it”.
The power of this technique lies in repetition — after 10 times writing “I feel bad because I didn’t socialize”, you start internalizing it and finding solutions naturallly…
Of course, this is all theory. I am still looking for the secret to having an immaculate vibe all days . But is is my latest theory, and the most promising one so far!