Writing any thing on the same subject can began to wear you down. Writing online can be particularly exhausting because of the need for quick turn around. Avoid the urge to give up and walk away when the same subject starts haunting you in your sleep. Let a variety in your writing and in you schedule help to boost your enthusiasm once again.
1. Spread out the work. Recently I had an order for over 100 articles on similar topics but written in the same format. After about six in a row, I start to feel like I'm repeating myself (and some times it feels like I'm saying the same thing over and over). I pushed myself to the point of a nervous breakdown to get the first half done, but I'm taking it a little different for the second half. I write one or two of the articles in between blog posts or other projects. I'm slowly getting the project done, and I'm actually enjoying the process this go around.
2. Take a break. It doesn't matter how much you enjoy the subject. If you sit in one spot doing the same thing for too long you will start to feel the burnout. Get up and go outside in the sun for awhile. Play a game with the kids and spouse (or just the spouse). Go for a short drive or an outing. A change of scenery and tasks is sure to give your writing a boost.
3. Find a friend. I have several online buddies (we chat through IM) that I can call on when I'm beginning to feel burnout. They are also online writers and are often going through the exact same thing I am. It helps to know that I'm not alone AND they usually know how to motivate me and get me back on track.
4. No more procrastination. There is nothing worse than having a due date pounce on you without having any of the work started. Begin the project as soon as you get the assignment and work on it in pieces. Use the due date to do any editorial work that might need to be done.
The key to avoiding writer's burnout is to write about things that you enjoy, create variety through different jobs (or your own blog), and spreading out the writing over a longer period of time. Scheduling can be one of the most valuable tools, especially for an online writer. Take a few steps to lay out your writing so that burn out doesn't fine its way into your career.