Who is your target audience?
When starting a blog, ask yourself: what is my target audience?
Do you intend to write for teens? If so, start researching on what would make young people read your blog. Some just talk about mundane experiences like shopping for new clothes, or beating their friends at DOTA or Counterstrike. Other writers get by with articles mostly about relationships.
If you want to cater to yuppies, you may share a common ground by writing about work, plans in life, career growth, and relationships still.
On the other hand, if you’re targeting people from a specific field, then you have to keep your articles related to their line of work. If you’re eying sales managers or the like, then don’t even consider posting articles about chastity education. Your audience and your message are interrelated.
Pick on what would interest them most, and you might even have them coming back for more.