Glad you asked this and I read through everything, because I, too, was told to have some kind of platform and presence to start building an audience. SO, that's what I did. I finally relented to do a twitter account and also made my author FB page.. and I linked them so that when I tweet/ed something it posted on FB as well. I also started an author WP blog to hold short stories, not commentary as such. I haven't updated the blog in a long while because I'm usually busy writing/editing or researching things for the book(s) I have finished. The blog is more or less to get a feel for my writing and genre. I have tons of stories to get down and put up but .. well life.. and I need a few more hours in the day. I try to stay active enough on twitter to get at least a few new followers each week, and I know if I were vigilant with it each day I'd build more,, but again life. HA! I"m glad though that I did this bit of ground work already so I don't have to go back and do it later if deemed necessary at any point. I do have personal blogs that I have done for years but they are under my real name, and I want to try and keep the two separated as long as possible. If I ever make a successful run of any kind, I don't think I'll care much at that point!
Good Luck with getting back to the typewriter!