I have experience tutoring my friends, family members and even my nephew with autism.
The way I start a session is introducing myself and what we will be going through in that session, I would ask for their strengths and weaknesses, so I can base the session on what needs working on and what we can just briefly go over so they have 100% confidence in different topics. If I am doing a tutoring session in person I would bring some sheets with me or maybe a book and we will go through that together while I explain to them how to solve the different types of questions, I will explain things has many times as they need, as they are the ones who are learning, I am a very patient person so going over the same thing just to get them understanding is very key to me. Sessions can go on as much as they need or want, I will push people out of their comfort zone at times just to try and get them to do the best they can, when I see or when they ask for help I will be there to easily identify what went wrong and how we can improve and get it right next time. If I am doing an online tutoring session I would have a work book with me, I would ask them to have some paper and a pen and then will help teach this way, at times I would even get a PowerPoint set up if it is easier for them to learn that way.