I don't know if this qualifies as a #SELHack, but one idea I find many schools turning to is that of an advisor. The advisory system works to create an adult connection for each child in the school, someone who they know is looking out for them and there for them. In my school, we had a program in which almost every teacher, admin and staff member were advisors. During 'Advisory,' which met once a week, we would have planned activities emailed to us by the Advisory Coordinator. We could do more or less of the planned activity depending on our students' needs. We also just had time to connect and talk. The Advisory group was multi-grade/age and behaved like a family away from home.
One other great part of advisory is it gives parents a consistent adult advocate for their child all through their years at school. Also, one adult knows the child very well, as opposed to teachers who must learn their students fresh year after year.
It is not a true "hack" in that it would be a lot of work to carve out time for Advisory in a school that doesn't have it already in place. However, it is an effective and straightforward way to build community and connection into your school culture. It allows every student to have a voice and feel seen.
Here is an article with some tips for creating an advisory program in your school.