Once a day with brushing and flossing. Mouthwash is a sometimes thing. I think I used it more when I was still having problems with my teeth (unrelated to hygiene) in the hopes that it would help somewhat. Of course it didn't, but I could hope.
I go every six months for cleanings, but because I've been lazy at times I still have problems with cavities (though I think I'm finally ahead of that now, thank goodness), so sometimes I'll have to go in an extra time or two. And then because of a thing that happened back in July I've already seen the dentist way too many times this year, hah.