This is an awesome question. I've actually been facing something similar lately, as you may have noticed by the reduced pace at GRS. When I just had a personal site, burnout wasn't an issue. If I was feeling drained, I just didn't post. Now I feel like I have an obligation to GRS readers. I feel compelled to post frequently. But this leads to burnout! Not a good thing.
To combat this in the past, I've usually forced myself to take a short holiday from blogging, usually just a day or two. I do something completely unrelated. Go rollerskating. Drive to see a friend. Build a garden. Whatever. Just anything to get my mind off the same old routine and refreshed.
Here's a strange thing: I've found that the #1 best way for me
to recharge is to mow the lawn. It must be something to do with the zen-like exercise involved. Whatever the case, mowing the lawn always brings a flood of entries. Yesterday I got four entries alone out of a half-hour mowing job. I can't explain it, but it happens nearly every time.