1. The plain white onesie and sharpie marker is a cheap way, simply write NO CIRC in giant letters.
2. I printed out signs for the door of my room, the wall of my room, the baby's bassinet, and I asked that a copy be put as the first page in our chart.
3. I told everyone who entered my room that he was not to be circ'd. (well, I might not have told the janitor or the food service people, but everybody else!)
4. Whenever possible, don't let baby leave your side. You can decline any middle-of-the-night tests (even weighings, hearing tests, and heel pricks can be declined) Simply say "we are resting now, please come back later" over and over. I had a few nurses mad at me, saying that they "had" to get a weight (or a blood sugar, or a hemoglobin, or something!) at midnight because that's when it was "due". I said "write mother refused on the chart and come back in the morning" They'd have to get the dr (OB or Ped) to argue, and they almost certainly won't call one in the middle of the night for that reason.
5. ALL tests can be done in your room, despite what they might say. Even the hearing test. Even the bath. Even the newborn screen. Even the discharge exam. EVERYTHING. Insist on it. Simply say "I insist that baby remain in the room" over and over. If you feel like it is getting heated and you need a compromise, offer to accompany baby to the testing room, but make it clear that you WILL remain physically touching the baby at all times.
Don't worry about garnering a reputation as a difficult mom, frankly they will be more careful with you and more quick to discharge you if you bug them. No doubt the nurses will call you the "freak" mom or something like that, they will be very careful not to do anything wrong, and they'll want you off their load quickly.
And you'll leave with a perfect, intact, son