I've been doing social services work for over 16 years. In that time, I've found that the most powerful tool that helps people trying to improve their lives is a supportive relationship. That's right, more than any specific therapeutic approach, I believe that the very relationship itself between client and therapist is what most benefits those seeking support. (For those looking for more academic terms, "supportive psychotherapy" is what best fits what I'm describing here.)
That said, of course there are some specific evidence-based tools that I do find helpful. Though I pull from an array of different approaches, I most often incorporate mindfulness, cognitive behavioral therapy, and motivational interviewing to help my clients build insight into what has them feeling stuck. Then, using that supportive relationship mentioned above, we work on incorporating this insight to move forward, all the while encouraging clients to become increasingly gentle with themselves.