Don't sneak out in the morning, it's tacky
PLEASE don't run away at 6am after screwing a stranger. You shouldn't be ashamed of the sex you just had. It's good you had sex. Yay you!
Now, if it's 11am and this dude or lady is still passed out and you're bored, sure you can leave. You are not obligated to wait until sleeping beauty has woken up if you have stuff to do today. That's not sneaking out -- that's just remembering you have a pile of laundry to do and groceries to buy. Peace out!
Actually, if you can keep the one-night stands at your apartment, that's ideal
If you've got the choice, bring the guy or girl back to your place instead of opting for his or her shitty apartment in Bumblefucknowhere, Queens. All of your stuff is at home. There is no stride of pride. You can sleep in your own bed.
NOTE: if you're averse to strangers sleeping over or have problems telling someone to get out of your place, go to his or her apartment.
Breakfast is nice, but it shouldn't be expected
Don't stick around in the morning with the expectation that this guy or girl is going to make/buy you breakfast. It would definitely be polite if they offered breakfast, but they are not obligated to feed you.
Don't ask for it. It's rude and makes things weird. Err on the side of caution. If he or she suggests breakfast, cool. If not, just go home and make yourself some eggs.
Feel out your goodbye
Hopefully, this guy or girl will walk you to the door (if he or she doesn't, a wave goodbye from the bed will do). Make your goodbye friendly and chill. Definitely don't try to come in for a kiss. Just give them a quick hug, leave, and go on about your day.
If he or she wants to kiss you and you're not down, just pretend to suddenly see a button on your shirt that might be falling off. Pretend that button is REALLY interesting.