You will be shocked at how much visibility harsh tags get people on twitter. A large number of people have been able to get their footing on twitter through numerous harsh tags that they have started. If you are looking for that way to get 500 twitter followers, start harsh tags.
Be careful though as you starting these harsh tags. Remember that your main aim is to get followers thus interest has to be your top priority. Interest here refers to picking the interest of the twitter crowd out there. You need to start harsh tags that people can relate to. Harsh tags of things that are actually affecting people in their day to day lives and harsh tags that they will definitely want to throw in a comment or to about. Do not be selfish and concentrate on things that are maybe only happening in your locality or things that only your friends can relate to. You need to have a global mindset and get to learn how to step out of your comfort zones. This will help you to appeal to a much larger crowd and will definitely get you those 500 twitter followers.