Avoid Saturdays. We were there last year and I have never seen so many people at Epcot - it was a shoulder to shoulder in all of WS, absolutely nuts. We left around 2pm and people were just flooding in, a CM standing at the exit was just in awe and said to us "I have never seen this many people here ever before!" Just nuts.
I agree with checking out the menus ahead of time, also. I did that, and I knew exactly what I wanted and where to find it. We did a couple laps just to check everything out (on Friday) and DD15 did find a few things not on our list, but most of what we ate we planned it. It is amazing, though, and we can't wait to do it again!