Agreed that New York City is well known for the carefree life that it proffers to everyone of its residents, it certainly does not mean that you let go of your dignity while staying at a hostel in New York. This is especially true given the multicultural background of the individuals that you would typically come across at any New York City hostel. In other words, you are a very representative of the culture or country that you come from.
Small gestures on your part can actually go a long way in conveying to your hostel in New York mates, an appropriate sense of camaraderie that you carry with you for them as well as for everyone else in general. For instance, while lying on your hostel dorm bed and speaking on the phone, make sure that you speak softly so that others around you do not feel disturbed by your conversation. Likewise, in case you are eating something, especially if that item happens to have come from your native land, it is appropriate that you at least offer the same to everyone around you. At the same time, you should make sure that you eat in a manner that befits dignity; instances being not dropping food around or making loud audible sounds while eating.
As you can clearly see, small steps taken in an appropriate manner can actually go a long way in conveying to your hostel in New York mates the fact that you respect their presence and cherish the same wholeheartedly.