I try to define what our goal is at the git go. Even if we veer off in other directions, having a clearly defined goal helps me to focus and take the process seriously, even if I'm feeling cynical or reluctant. I've had half a dozen rounds of therapy that lasted between six months and five years. This round, at 10 months now and counting, is about sorting out how my illness has impacted my work life and sorting through all that to get to a better place.
Past rounds have been about relationships, family, and recovery from trauma (the longest stretch).
For me, therapy works best when I'm on meds, the right ones. Otherwise I just come in and cry for an hour per week.
Good luck!