It's not so much what you write about as it is who you write for.
Most people can write a good review or re-tell a sexual escapade or recount a piece of advice, but that's no good if you're not targetting the right audience. Look at your own experience and try to see who will want to read what you're going to be discussing. Alternatively, you could write your blogs centred around a certain niche of readers such as LGBT, BDSMers and so on.