I use Goodreads and in my list I have books from different topics/genres. At any given moment I try to have at least 1 book from each topic in my “currently reading”. If I finish one, I go to the next. And I try taking the oldest ones waiting for me to read them. Sometimes I delete few, according to my personal taste’s evolution. My topics are usually “fantasy”, “hobby”, “mental health”, “people”, “fiction”, “sci-fi”, “thriller/horror”, “work related”, “science”… my favorite shelf is fantasy I move those a bit more than the rest, the fastest shelf is hobby due to the size of the books. I organize my list from date added, that way I keep adding but don’t forget those old ones that I wanted to read years ago.