Mathematics from 11+ to GCSE level, re-teaching full topics and giving practice questions

I currently study Dentistry at university and I achieved an A* at Maths A level and I have been tutoring students in Maths from 11+ all the way through to AS level, for the past 3 summers in a row. I reteach the topic in full to the students before giving practice questions, and assisting them when they need help, as I find that teachers in school sometimes miss out important pieces of knowledge or useful tips and tricks to make calculations much simpler!