You can't understate the significance of word of mouth in retail, especially in the catering business. That's why it remains important to establish a database of clients who you can rely on for steady business, and for future referrals as well. In many ways, getting started will prove the hardest part of the business, since at that point you can only ask customers to trust you without having established a record of your talents. However, if you know where to look and how to ask, you can have a viable database in a short amount of time.
Print promotional and marketing materials. You don't have to go all out. A simple, descriptive menu -- printed professionally -- will suffice. Presenting something tangible for a customer take with him after you meet makes sense. Also, consider taking pictures of the food you make. Even if you haven't had your first customer yet, cook some food for your friends and family and snap a few photos to include on the printed menu.
Offer a promotion or incentive to get the ball rolling. Don't sell items at a cost so low that you can't make a profit, but sacrifice a bit in order to attract new clients. For example, offer free appetizers for dinners over 200 people. Provide incentive for referrals, too. If someone who has used your services convinces a new customer to hire you, give them a percentage off their next order.
Market to your target audience. Attempt to drum up business with clients most likely to opt for your fare. For instance, if you operate a deli-style catering business, canvass the office complexes in your area where corporate lunches occur regularly. Also, medical business parks, where many pharmaceutical reps work, offer a potential clientele for this type of cuisine as well.