Thinking about what @teabreaks says, I think blogging is tricky, because you need to tap into an audience. I remember my Stepdad wrote a blog for 6 months about him building a traditional kayak from scratch and he managed to get a fairly big audience (much to his surprise). He had always intended to stop the blog after the boat was finished, so his success ended there.
This example is extremely niche, which may explain why he found an audience, because there were not too many other people attempting this project, but there were other boat enthusiasts and woodworkers that wanted to read about it.
When it comes to crafting, the market is very saturated, and the audience any of us are looking for probably just follow Kirsty Allsop and leave it at that
My conclusion is that the best way to make a blog work for a crafter is to find a very personal slant and stick with that.
When I think of one, I will start blogging, but not until then.