Act, dress and carry yourself in a confident and professional manner, and there s no reason to worry if someone will take you seriously. Some people wont, and nothing is going to change that.Truthfully this is a good way to get business, but it takes a lot of persistance. Be fully prepared to be turned down many times, which is something that happens with any service type industry. Make sure that your price in on par with what these business owners can spend. Make sure that your ability and work justify what you charge. Make sure that whatever you hand out, be it a business card, post card, or a full page, is very clean and professional and printed on quality paper.Also, make sure to target businesses with no website or with homemade websites, etc.. It makes no sense to go after someone with a strong web presence in situations like this. When you do get customers ask for referrals and offer them compensation for it.
Don t walk in. Make your initial contact via e-mail. Find out the name of the person in charge of advertising for the shop, and e-mail them with your proposal and a link to your portfolio. Maybe do a mock-up of the type of home page you could create for them. Don t meet with them in person until they re already hooked. By then it will be an interesting surprise, and not a turn-off, for them to discover how young you are. (By the way, your site looks very professional. I m glad you re in the UK or I d start worrying about competition!)