Ask for a Corner Room
If you book early enough, this one is all but guaranteed to score you a larger room with more windows and natural light for no additional cost: Ask for a corner room. Because of the way many hotels are built, corner rooms end up being slightly largerthan other rooms without technically being categorized as fancier luxury suites. If you book directly by phone, you can mention this when you make the reservation. Or you could simply inquire about the option when you check-in.
Lay on the Charm
Tell them how much you love the hotel or the city you're visiting. How this is your first time staying here and would love the best available room. If you want to tell a little white lie, mention that you're celebrating a special occasion, like an anniversary or promotion. The person at the front desk may be generous enough to offer up an upgrade or even send up a treat or a bottle of Champagne to your room.
Report a Problem
You want to be careful with this one. It's a fine line between being "a discerning customer" and a "dick with a complaint." But hotels want to make sure their guests are comfortable and happy, so if your first impression of your room is lackluster or you notice something wrong upon check-in, go down and let them know before you unpack. The front desk staff is likely to go the extra mile to give you something that elevates your experience.