time consuming techniques: tweet interesting things fast way: use twitter friend finder from http://www.vicconsult.com/twitter-follow-friends-finder/
Regular tweet, don't always tweet about your business, some time tweet about latest twitter trend, this will help you to attract more visitors towards you, and you will get more followers, participate in questions or discussions, use your keywords in your tweets with # in front of these keywords, upload your images and share this with other..Follow others and also allow them to follow you easily. Also promote your twitter account with the help of your other Social networking accounts.
Use Twitter to give things away or provide coupons and discounts for your goods and services. You will easily attract Twitter followers targeted to your business if you offer them something they cannot get elsewhere. Moreover you can buy twitter followers, try SEOclerks, you can find many freelancers on this site providing twitter followers at a cheap rate.