I have experience in mentoring several students between 11 and 15 years old to assist with Maths, Biology and Chemistry for their GCSEs. Additionally, I volunteered at a primary school for months, during which time I assisted in a range of class subjects from spelling and reading comprehension to RE to mathematics. I have two different approaches depending on whether I am in person or online:

Online, I tend to use live video calls with an online shared workbook on which I can demonstrate steps towards solving an equation while also seeing how the student is going about answering a question. This allows me to make every step clear and to spot errors when they are made in the workings out.

In person, I prefer to use paper to set out all my steps, and the student can hold on to this if they'd like to practise in my absence. Depending on circumastance, I may bring a computer to refer to exact wording of specification points in early sessions when I am less able to plan ahead.

In both, I have a range of exercises I like to run through, including "Reword!" wherein a recently explained topic will have the common words to describe it banned, so the student must draw on their genuine understanding to remake that explanation in their own words. To ensure a good experience evry time, I appreciate when a broad topic is requested prior to the first session (e.g. Struggling with meiosis and mitosis at the moment.)