I would suggest getting there at least an hour early to get a spot next to the railing. Just sit back and have a snack or a drink and watch the people go by.
You can see video of it in my EPCOT video below, too.
We have camped out for over an hour getting a great spot. IllumiNations is our favorite thing at Disney (maybe why we are getting married there next month and having an IllumiNations Dessert Party). Yes, you can see it from around the lake but I have to be right on top of it and make sure there are no overhaning trees where you are. The fireworks and lasers are up in the sky but we have had our vision limited due to trees.