This is not for the feint hearted. You need to be thick skinned and have, or develop, an immunity to rejection. This having been said you need to remember that people buy from people and this is the most effective form of marketing.
You may not get to speak to the decision maker first time round but you should be able to establish their identity (name and position) and contact details (personal e-mail address or direct telephone number). Ask for their business card.
In any event you should get to know the receptionist so that they know you next time you call. Also, leave your business card and a leaflet, with a request for them to be placed on the decision maker’s desk.
Cold calling works best (is more efficient) where you have a number of businesses in the same vicinity such as a high street or shopping arcade, a business park or industrial estate.
You can increase your chances of success by doing a bit of research first. Spend some time over the week-end, when less people are about, assessing prospect’s premises – the better presented / tidier they are, the more business like the owner is likely to be.