Whenever there are several posts that should be updated, I prefer to update them all at the same time. That way I don't have to create a todo/reminder to update them later on. By far the most common update is simply changing the tags.
The only problem is that it bumps up all the posts to the top. I'd prefer if it didn't, but I guess that's how the system works.
Is there a specific time of day I should do it, or is doing them right when I notice they need to be updated fine?