@Lizzie, it took me some time to learn how to strike this balance, but I think I've got it worked out now.
Initially, I allowed access to all spaces in the house, but soon realised that this left nowhere for me to hang out if I didn't feel like interacting with my guests (especially in summer when I have a nearly 100% booking rate). So I have now stated that the lounge is not accessible to guests 'unless specifically invited'. I like to have this area to myself as it's also where my home office is (I work from home). And as I've said before, there is nothing more awkward than watching TV with strangers!
I have also changed the rules around kitchen use - initially, guests were allowed to use the stove and oven but this meant that I attracted mostly guests from a nearby region who would spend hours cooking rather than going out to eat, meaning that I often couldn't get into my own kitchen to make dinner. This was a major cause of resentment and frustration for me. It also meant that they would spend the evening eating (often rather loudly) in my dining area which is open to the lounge, meaning that again I had little privacy. Since I have stopped the use of the stove and oven, I mainly get guests who will eat out and when they come home, they mostly go and hang out in their room rather than the common areas.
I ocassionally block off my calendar if I am going to have a few friends over or friends staying. However, I often have people for dinner or cards or just popping in, so I will try to let my guests know if this is going to happen if I know about it (which I don't always!). I had a lovely guest recently who said after the 3rd person dropped in, "I love how communal this house is"!
Finally, I have installed a lock on my bedroom door that can be locked from both the inside and outside so that I can lock up my room if I'm going to be away (just in case anyone decides they want to poke around in my underwear drawer!).