Lists work really well for me. Some popular lists like this[1] is a great place to start. Also on each film's page at the bottom, you can find lists it is on. So if you like a movie particularly well, you can find similar one in those lists. Most of the lists are not generic genre/actor/director based so I find really good stuff there.

[1] https://letterboxd.com/dave/list/official-top-250-narrative-...