Don't write for "an audience". You have two main options on who to write for: yourself alone (i.e. a public diary) if you have the discipline to keep it up, or

Don't write for "an audience". You have two main options on who to write for: yourself alone (i.e. a public diary) if you have the discipline to keep it up, or some specific person, e.g. your mom, your spouse, your officemate. Either way, don't worry about your readership. It'll come or it won't, but the surest way to be a bad blog that can't attract readers is to actively try to attract readers. Good luck!