The most valuable tool I ever got (as a tutor/teacher) was Socratic Questioning. Students not only benefit from its application but it also helps to impress upon them the value (and relative skill) to asking thoughtful questions.
I don’t mean to sound like a Mom for Liberty, but to my mind, the American public education system (probably others) is not about developing intelligence but rather preparing children for work and keeping them busy/safe while their parents work, and I’d argue it’s not very good at its primary function. The ones who escape with curiosity, capacity, and confidence intact are woefully rare if you care about power to the people and thankfully rare if you care about keeping people easy to control.