How can I become a "partner in collaboration" with the teacher instead of clashing?

Parents are "experts on how the child is at home," and teachers are "experts on how the child is in a group." If either kind of information is missing, support is only half complete. The tricks: (1) before making requests, first thank the teacher for what they're already doing; (2) offer "at home, this works well" as information (not as an instruction); (3) when a problem comes up, say "I'd like to think through a plan together" rather than hunting for who's to blame; (4) always report back when something works. A relationship where the teacher feels "this parent is easy to work with" ultimately raises the quality of support for your child.