You should at least tidy up a little before they come.
I've just been to view a rental, it looked lovely in the photos, all brand new inside, and it's not cheap.
When I first walked in it stank of sweatyness, there was junk everywhere!
there was dirty knickers and socks on the floor, ice cream wrappers in the bathroom, some kind of weird comic/animation naked lady pictures up.
The estate agent who showed me round and apologised for the mess, and said the guy who lives there with his mrs had just left and had tidied up before he'd gone and it was a lot worse before 
Aibu to think that if you should at least tidy up things off the floor if you know people are coming to view your house? Especially if it's rental as it's not even your house!