My complaint about TS4 has been that I did not like how game play basically tells you exactly what to do.
I prefer to be given a goal and choosing my own way about reaching it.
I hope Fame is like this.
There should be a smart way to do it and a not so smart way.
Perhaps seeking fame before you have talent give poor returns. If that is the case I would be more focused on getting my sims fame worthy before being concerned about their fame status. So, basically skills and career levels before watching their fame meter.
Maybe there are multiple things you have to have going on to ride fame waves.
I have experienced sudden surges in fame that gets me to the next star, but I am not sure what I did to achieve it.
I would test this out, but I am having too much fun with my current sims. :)