The most difficult part is common to much of life; being consistent. I have read the theory that one should blog daily or weekly irrespective of any new content of value. So if you ever wondered how the internet got to be a mass of pointless babble, that kind of approach may be one of the reasons.
Excessive demands on time is a common comment to encounter as a valuable site fails to be maintained and goes to the great webhost in the sky. I prefer to restrict my posts to things that I feel to be of value and try to ensure that they are the sort of information I would like to read myself.
Well that's my feeble excuse for the paucity of postings recently, now watch me contradict what I have just written with a blitz of sub-standard posts over the holidays. :)