First of all, identify your target audience. Based on the analysis of such components as: age, social status, income, marital status, professional activity, depends on the initial predisposition of people to your offer. Once you have made shaped the portrait of your buyer, you should now be able to spend more time where your potential customer may be. For example, if your advertising services include conducting promotional events, the organization of tastings, distribution of gifts for the purchase of goods, etc., then your client will be an entrepreneur in the trading sector or the representative of a major organization associated with the food industry. To each other to meet, should visit the exhibition, open business conference, etc. Visit this kind of place, and in an informal setting such as a coffee break you will easily be able to strike up a conversation with the right people and offer your advertising services.
Immediately "pounce" on a customer with their proposals is not necessary, it is necessary to make a favorable impression and to demonstrate intelligence. In advance, prepare a card that lists your contacts and briefly describe your activity profile, i.e. the gains that the client will receive if they decide to cooperate with you. For this card to attach a small flyer or pamphlet and to convey personally into the hands of your potential customer.
When you start actively offer client their advertising services, contact numbers and visual graphs illustrating the effectiveness of conducted promotional events with other companies. The successful experience of the competitors will make you wonder even a "veteran" managers of the future cooperation with you.