A blog post is thoughts from a moment in your world. Sometimes they can be serious, but usually they are light and friendly. The first skill of blog posting is remembering that.
Getting blocked is the biggest risk. If you try to write a best selling novel every time you will get blocked. If you insist on exploring the full thesis of a topic you will get blocked. Do what you can right now and don't let what you can't do stop you. I'm changing my blog image processing procedures, so for a while, my posts won't have images. I'd rather have images, but that doesn't mean I don't have something to say.
Blog posts should be short. A blog post is friendly conversation with your readers, not a trap to ensnare unsuspecting citizens.