Darren Rowse explains how to schedule your writing times for maximum blogging success. The other day I offered some business blogging productivity tips that go well with Darren's theme here.
By setting aside a specific time each day or each week to blog, you can accomplish more and write with more focus. Remove distractions - you might even find it necessary to go "offline" to write some or all of your posts.
And I agree wholeheartedly with Darren: in general, you should make that special blogging time as early as possible in your workday. This will help you concentrate better and finish this most important aspect of your work before all else.