I “do my business” with the door open.
I live alone, so I have the house to myself all the time. I never close the bathroom door. During warm weather I’m pretty much naked all the time. 
If I ever get the house to myself, I’ll let you know.
I end up having the house to myself most of the time. The novelty wore off about 20 years ago. I do pretty much the same stuff I do when I don’t have the house to myself, except I talk to myself more.
I’ll know if you don’t!
play loud music
Nap.
It’s a rare occasion for me nowadays, so I go all Risky Business: play the stereo loud, sing to the cats, run around in my underwear, watch TV shows my family would mock…okay, pretty much just the very beginning of Risky Business, but it passes for fun for me nowadays.
I work at home, and my partner lives next door. This means that I’m alone with the 2 cats most of the time. I can pretty much work when I want, eat when I want, sleep when I want. And I don’t think the main bathroom door has been closed in 8 years.
Clean. Read in the living room with the cats. Make eggs. Haul away hoarder loot. Listen to music on headphones knowing nobody is going to scare me to death by shaking me to ask me why I’m listening to music on headphones.
Seriously, I’m the first to say it?
Masturbate.
I order fried chicken and play Diablo 3 all day.
Pee with the door open.
Dammit, beaten by the OP!
I do pretty much the same thing as when my husband is around, except that I have to pay more attention to the cats. That’s not my choice. I mean, I love the kitties, but each of them requires a lot of individual attention, and when my husband is home, he does his share of kitty petting.
He’s leaving to go on a hunting trip in about four hours. Then it’s gonna be just me and the cats until Sunday evening. I hope we all survive.
Like a motherfuck!
This is odd. Having a small, brilliant and easily bored child in the house most of the time, the great luxury of being alone is being able to actually close the bathroom door for once, and not having to crane my neck listening to make sure nothing important is being disassembled while I sit there.
I also watch grown-up TV shows. You know, the shows like HIMYM, Big Bang Theory and Sleepy Hollow which are either so creepy or so given to foul language thta I can’t take the risk she’s out of bed and sneaking around the house while I’m watching them.
Eat chocolate and peanut butter, and garlic, all the things that smell like death on a cracker to Celtling.
Catch up on the laundry.
I really need to find some fun, don’t I?
Sing.
Perhaps you misread the OP. 
This is the perfect setup. How did you arrange this?
Ive suggested many many times that DH and I get a duplex or split the present huge house into “his” and “hers” zones. Separate everything except a common bedroom, and even then, a separate bedroom is nice for sick days or snoring loudly. We get along fine when traveling (neutral territory) but we are each too territorial for sharing spaces long term.
I need my areas for my business undisturbed. Creativity cant be scheduled, even tho we do arrange for certain areas to be used for block times. Grrr.
I think *you *misread. He’s talking about the front door!