I have 3 sups. One I see once a week, but as a research group rather than specific to my project (though I can talk to her about stuff if I need to) My main sup I see when I need to. It probably works about abotu once a month, and I arrange meetings by calling his PA as emails tend to disappear! My other sup I see once a month, and we arrange these meetings at the previous one. I have more contact with his post doc, without whom I don't know where I'd be!