I always approach a new social media tool in a sort of exploratory way, as if it essentially exists in a world by itself. Keyword search to find interesting thoughts/ideas that align or intrigue. Follow those folks, then watch the feeds of those folks and pick off/follow the people they follow. Iterate. I don't attempt to create a follow list based on my previous social media accounts (though of course there will be a handful of people of specific interest that I will seek out). How do others build a follow list here?