Well - taking your question literally, no, not just anything. You can combine anything but it may not look like what you want. For example, mixing two brick textures will still look like repeating bricks and they would not necessarily blend well. But qualifying with "suitable" textures and "suitable" masks, yes - there is a lot you can do to make the repetitions less obvious.

---

Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)