A great blog is not difficult to create and maintain.  There’s no secret.  Having good content; unique content; relevant content is the key to successful blogging.  Keep your readers informed and you’ll keep your readers. 

Take Healthline, for instance:

"Healthline is a specialized medical search engine that offers high-quality, authoritative information that’s easy to find, even if you don’t speak medicalese."

Carefully listening to what the market needed, Healthline saw a need and filled it well.  In fact, their reviews are glowing, including this one from Chris Sherman:

"Healthline is one of the best, easiest to use health information sources I’ve yet found on the web. The "patient friendly" interface combined with first-rate, vetted content make it an excellent resource for anyone researching health related information."

Offer your clients something they feel they can’t get elsewhere.  Always keep it timely and fresh.  Discover what your clients may need to read and you write it for them.