It used to be a todo list set up where I just check off and add whatever books caught my interest but it wasn’t very shareable so I moved onto storygraph which I liked more than goodreads as the data visualization and breakdown of books via tags and moods gives me a better idea of where I tend to lean in books I seek out and which genres I rarely touch at all.
Personally, I keep a Note on my phone which has a list of everything I read, the author, the format (physical, ebook, audio), and my rating out of 5. I then occasionally transfer the data over to a spreadsheet I set up which gives me stats about the genres I read most, authors I like best, etc.