Have a look at other writers pages. Share funny/interesting writing related posts & articles, snippets of your writing. Add links to your own works if published, or to your blog etc. Photos linked to your writing life/interests. It's anything that is part of your journey that others may find interesting. Raise questions that you think followers might engage with. I have one but I'm not very active with it, as I have others relating to the gites we run as a means of income and the dog refuge we volunteer with. They take up more time to keep on top of & my enthusiasm for my writer page tends to wane, so mine is probably not the best example!