Your next step is to find your target tweeters. I can speak for Etsy sellers and say that Etsy sellers are the best Etsy Buyers. So start looking for Etsy shops on twitter.
For other online sellers, ask yourself, who is your competition? What companies do you strive to be like? That is where you want to start.
I am currently not publicly endorsing any auto follow twitter tools, but if you google search “Twitter followers free” there are a lot of programs out there to help you start following people that are either in your industry or interested in it. Choose your search words carefully as most of these are free trials, and will end after you get X# of followers.
Example: Etsy Shops – Follow tweeters with keyword ETSY.