Today's successful retailer needs to be nimble when advertising products and services, and there's no better--or cheaper--way to address that challenge than by painting store windows. Window art and copy, when done right, not only attract attention but also create excitement in shoppers for what's going on inside a store. Commercial window signs can drive foot traffic and sales without threatening a retailer's bottom line.

Design the sign to be painted by using page layout software (such as Adobe InDesign) or by scetching it out on grid paper.

Prepare the window by removing any existing art, lettering or signage with a paint remover. Next, use a window cleaner and clean, soft rags or paper towels to remove leftover paint remover as well as fingerprints and grime. Make sure no soap film is left behind, and allow the glass to dry completely.

Place painter's tape around the periphery of the window to protect the wood and hardware holding it in place. Alternately, slather the window's periphery with petroleum jelly. Paint won't stick to the jelly, and you can remove the jelly with just the wipe of a cloth.

Transfer the design to the store window. If you used a computer to create the design, take it to a print shop to have the image printed large enough to fit the window so you can trace the design's outline using this template. If you used grid paper, recreate the grid on the window surface, then freehand the letters and images with a grease pencil or chalk.

Paint the sign. Consider applying multiple coats, especially if you painted the sign on the outside of the window.

Clean up any stray paint strokes, splotches or spills using the same tools you used to prepare the window. Then remove the painter's tape or petroleum jelly, and spot clean any fingerprints or smudges.