Advertising. Ads come in all shapes and sizes but the first step in creating the design is knowing the general format required such as a yellow pages display ad, a small space ad in a daily newspaper, an upscale magazine insert, or an online graphic ad.
Direct Mail. Business mailings can take many forms from postcards to letters to brochures to multi-document packages. You (and the client) have to decide which format is best based on the amount of information to convey, the purpose of the mailing (name/brand recognition, develop mailing list, make a sale, etc.).
Holiday Message. A greeting card may seem the obvious choice but a holiday letter, newsletter, customized calendar, or postcard are also possibilities for both personal and business holiday messages.
Identity Package. Although business card and letterhead with envelopes are standard elements of an identity package, not everyone will need them all and other related pieces may be required such as note cards, notepads, rolodex cards, labels, fax forms, and custom invoices.
Sales Information. To make the sale you need to describe the product or service. How much detail you need to provide and how it is delivered can dictate what form the sales information will take. Brochures, fliers, price lists, print catalogs, and online catalogs are some formats you may need to consider.
This is just a sampling of some of the typical document formats created with desktop publishing. Once you know the basic format, it's time to start brainstorming on the specific form the document will take such as vertical or horizontal business card, six-panel or eight-panel brochure, or standard or oversized postcard.

