I've visited a lot of blogs and there's something that I notice in quite a few of them: no contact details! The only way a person can get in touch with the blog author then is via a comment, which can be made open to the public.
This is not a problem when the blog author is not a writer, designer or someone who is selling his services. This becomes a BIG problem when the person is open to receiving clients, does not have a website with a contact form and conducts all the correct marketing procedures to get an audience to visit his site.
If you are looking to attract potential clients or even are open to the idea of getting new business, ensure there's a way you can be contacted. Put an email or phone number up on your blog where it's visible. And don't make it complicated. There's nothing that's going to send a potential client running off to your competition faster than if he has to play 'search for the contact details' on your blog.