Most horoscopes work because of the forer effect, which is an application of positive bias. Now, if everything we do with these "horoscopes" is based on this effect, then there would really be no appreciable benefits of this project. However, if one could describe a typical important crisis/situation in a significantly vague manner, you could perhaps get people to recognize an important problem in their life that they have been neglecting. Then, perhaps give some generic advice that, thanks to our brain's heuristics, brings a solution to mind.

For instance:

You are facing an important choice, and you haven't taken the time to think about it for five minutes to see if there is a better action than the ones immediately apparent. Make some time right now to think about it, and see if you can come up with something better.

Just typing that, I actually recognized a personal issue that's been generally percolating through my mind recently, but I haven't explicitly devoted any time to solving the problem. I'm going to take my own advice now.