Compromise on what you're looking for.
Looking for an apartment together is really fucking fun. It's also a lesson on the art of compromising.
She needs a walk-in closet; you can't live without a living room large enough to house all of your gaming systems. Looking for apartments, particularly in NYC, means that neither of you might get what you want, let alone both of you.
Meet in the middle and know the difference between what you need vs. what you want. You'll both know when you've found "the one" because it will be the place you both can agree on.