Open a new document in Illustrator. Enter the banner size in the Width and Height section in the New Document box.
Click on Advanced and make sure the Color Mode is set to CMYK. Most printers are CMYK-based, meaning they print using cyan, magenta, yellow and black. Click OK.
Open your photograph in Photoshop. The photo should be simple and bright and adequately communicate what you are selling, promoting or displaying.
Go to Image > Image Size and make sure the photograph is at a resolution between 200 and 300 pixels per inch. If the image is too small, individual pixels will show on the banner.
In the Image Size box, uncheck "Resample Image." This will lock the pixel information and adjust the resolution accordingly when you change the size.
Adjust the width of your image so that it is equal to the width of the banner you opened in Illustrator. Click OK.
Go to Image > Canvas Size and adjust the height of your photograph to coincide with the height of your banner. A dialogue pop-up will warn that some information will be cut off. Click OK. If you are unhappy with the clipping, hit Ctrl-Z to undo the last action and open the Canvas Size box again. Use the up or down arrows to adjust which parts of your photograph get cut off.
Go to Image > Mode > CMYK color. If the colors in your photograph appear dull after doing this, go to Image > Adjustments > Hue and Saturation and adjust the saturation to your liking.
Save your adjusted photograph as a JPEG file.
In Illustrator, go to File > Place and choose the photograph you just saved. The photograph will appear in the bounding box. Adjust the photograph so it is inside the bounding box.
Choose the Text tool and click on a random area on your screen. Choose a simple, easy-to-read font and type your headline, which can be a business name, a sales promotion, etc. Avoid thin or script-like fonts.
Adjust the color of your font for the best readability. Add a rule line around the text if necessary, or lower the transparency of the photograph by going to Window > Transparency.
Place the text in the upper portion of your banner. Adjust the size as needed, without covering up too much of your photograph. Leave at least a quarter-inch margin so the text will not get cut off.
Add the company name or a logo to your banner. This should be smaller than your headline, but not so small it affects readability. Don't use more than two fonts in your banner, because this can look too complex to read at a glance.
Add contact information such as a phone number, e-mail, address or Web address to the banner. This should be the same size or slightly smaller than the company name or logo. Use guides to line up text.
Make size and placement adjustments as needed for even balance. Make sure text is aligned correctly and looks clean and sharp.
Save your document as an Illustrator file.
Go to File > Save As > Adobe PDF and save the file in the appropriate folder. PDF files are widely accepted at most printers.
Choose "High Quality Print" in the Adobe PDF Preset drop-down. Click "Save PDF."