Don't repeat the subheadline
A terrible blogging writing mistake (I hold my hand up and admit that I do it all the time) is to restate a subheadline as the first sentence of that section.
Here’s an example Subheading: What’s good about (topic) First sentence: There are many good aspects of (topic) which we should consider.
It’s pointless and waffle.
Let’s get into the heart of the topic or at least provide some extra information.
Again, I do it all the time but that’s part of the value of editing.