Find iconic images that portray Broadway. Look for images that instantly communicate this unique geographic setting to the audience. Do research on Broadway, examining photographs from different eras, and it will become clear why they call it "The Great White Way." Broadway's theatre district is ablaze with large, lighted marquees. Other iconic images include sidewalk "sandwich boards" touting ticket sales, dark side alleys (like Schubert's Alley), bricks, and stage door entrances. Take these central images and pare them down to their "basics." All that is needed to convey the idea of a lighted marquee, for example, is the outline of a large sign created with lights, either real lights or painted "lights." Or, eliminate "hard" scenery altogether: Consider using one large or many smaller rear screen projections of real photographs of Broadway. Rear screen projection material is readily available and can be reused in other productions.
Think in terms of layers rather than one or two large set pieces. Combine several smaller elements: scenic panels flown from the sides of the stage, a gobo projection on the cyclorama, ground row flats along the sides and back of the stage at the floor level. Build up layers of a New York Theatre look from these many smaller parts. These smaller pieces will not only tend to be less expensive to construct than a large set piece but will be easier to strike quickly at the end of the scene.
Use the rules of perspective. If you want to convey the impression of looking down the entire length of 42nd street, line both sides of the stage with scenery that gets progressively smaller and closer together as the pieces recede into the distance at the back of the stage. Lower the heights of scenic objects and make any details smaller as well. If you're using real lights inside set pieces, make the diameter of the lights grow smaller for extra realism. Use just the exposed tips of tiny light strings for "far away" pieces, and larger lamps the size of refrigerator bulbs for set pieces closer to the apron.
Maximize the look of any hard scenery with strategic lighting. Carefully planned stage lighting can make or break any New York set. For example, if you're incorporating real string lights into "marquee" scenery, be sure not to wash out these lights with careless stage lighting. Focus lights away from the scenery in this case. If the marquee lights are painted, use a reflective paint and then "light up" the paint with carefully focused instruments. If your marquee lights are colorful, remember to shoot colored lights across the stage from the wings and 'brush' actors with stray color to simulate the real reflective properties of lights along the street.