Don't code in your sleep
I spent nearly all of yesterday editing and cleaning up some code on one of my websites, somewhere between 750 and 800 pages worth. However many months ago that I'd first created some of those pages I was apparently asleep at the wheel while I created them. They worked somehow and looked okay, but I'm just not sure how. I'd done stuff such as opening a line with an 'h4' and closing it with '/h2' - and that just ain't right! Must not have had enough coffee in my system that day.