here is how I do it.
first I go to Twitter Search
then I type in my main keyword the largest broadest keyword there is in that niche like dog training for example.
you will then get a list of all the people who used the word dog training in there tweet.
then all you do is visit there blog and post a helpful or thoughtful comment on there blog. you are not doing this for backlinks.
then go back to the tweet and use the reply feature to make a thoughtful reply thanking them or commenting on there tweet of blog.
this method is so simple that you can sit down and easily add 100 twitter followers anytime you want.
this method also works great for recruiting affiliates for your product.