Already thought of another one only a few minutes after I posted the first 5.
#6) NEVER WEAR NK PARAPHERNALIA WHEN AROUND A NK IN PUBLIC!
If you happen to find out that Danny is at the Smoothie King down the street, don't leave the house wearing your Full Serivce concert t-shirt! This gives you away, basically screams "I'M A FAN!". Of course you want them to know you support their music, but you don't want them to run the other way before you have a chance to tell them that. If a NK sees that someone wearing a NK t-shirt they can only assume that more will be arriving shortly, and they make their visit quick! Want more time? Leave the NKOTB earrings at home.