NewElthamMum, I don't know the etiquette either but I am more than happy for other people to add their own answers. It's always interesting for me to learn how other families do things as well.
Yes, maybe I should have said at the beginning, I don't speak for all home educators, of course, and many people's approach will be totally different to mine. I know families who allow their children to choose their own bedtimes or to have unlimited screentime if they want to, which is not how we do things at all. At the other end of the spectrum there are families who literally do school at home and sit down to timetabled lessons every day. Everyone is different and I can only answer questions from my own personal experience and philosophy.
I can imagine maths, languages and music work well with a structured approach. I guess mine learn music in a structured way as well, as they attend music lessons. But my eldest has taught herself to play the guitar, through books and trial and error, so there's always room for autonomous learning within a structured subject.
Stationthirteen, if I had a child who was unable to learn their chosen methods at any subject, of course I would help them if they wanted me to. I don't say "Sorry, learn by yourself or not at all!" My eldest had trouble learning music theory at first and I worked through a book with her until she got the hang of it and wanted to work on her own again.
At the moment, maths and english GCSEs are required for all students who want to study at college or in other further education, so I'd do whatever I could to help all my children achieve those. DD1 attended classes once a week at a local college to get her up to scratch with English. Ironically English is my speciality but she didn't want to learn at home 
. To be honest in some ways I'm glad, because I find the English language exam the most ridiculous hoop jumping and I think it would have infuriated both of us to work through it together if she'd chosen that route.