My first year as a lead (art) teacher I was told to incentivize my classroom. I had a group of students who didn't want to participate in activities, projects, or learning. I started a Friday donut club. I would write a note to every student who earned a donut through finishing projects and kind behavior. The note would say something nice about them and that I was proud of them. They brought the note to my classroom and I gave them a donut and told them in-person how proud I was of them. This seriously was a game changer that year. I do things differently now that I know all of my students, but when I was first establishing a relationship this truly helped.
...the most successful thing we did together was the "car wash". We learned how to give compliments to each other, and the person sitting in the center of the circle would get a genuine compliment (character-related) from each person seated in the circle as their "car wash" so the they emerged feeling fresh and clean! Took a ton of time, but was a true community builder we all loved.