Been to a lot of character meals..... great way to meet and enjoy characters without lines. Here's my best tips!
Many waiters will tell you how the characters come (the order, if come one after another, etc.), if not... ask. This can be helpful to know when to go eat (for the buffet meals).
Make sure you know how to use your camera! Some settings will result in a low quality image that will be hard to get a quality print in larger sizes. Use the highest quality settings and just bring lots of extra batteries and memory cards.
Have your camera ready and get UP from the table. Interact with the characters. Our best photos are those interactions, not just the plain strike a pose and smile shots. Encourage your children to do something funny... kid around with the characters, ask them questions, flirt with them, give a high five or something. I think it's helpful to let the characters know what you're doing in case they have trouble seeing. For example, I'll say something like, "Hey Pluto, how bout a high five!". Or just strike a really silly pose with the characters.
At some character meals, the interaction is "built-in"... at Hollywood and Vine, DS loved dancing with Agent Oso.
Video Here. And the breakfast food was fine even though there are reasons to complain about the lunch food quality.
And enjoy the food too. The food quality is not always sacrficed because it is a character meal. The quality of breakfast food at Cape May Cafe, 1900 Park Fare, and Tusker House was outstanding. The food quality at Garden Grill was pretty good too.
Ask someone at the table next to you to take some pictures with your camera so you all are in the photo... then return the favor. (Oh... and I always have an extra camera just in case it gets broken).
Put the autograph books away... Interact and take photos FIRST.... then pull out the autograph books when you are done. Now, I like some photos of the characters signing the autograph books (and some characters are quite silly with it) but the best photos are the action shots.
Get autographs on things other than books. We like t-shirts with the characters on them. Also... last trip, we did pillow cases. These were great.
When the characters are coming, get rid of the dirty dishes or move them out of the way to the back of the table. Don't want that in your photo.
I like tables against a wall... that way, use the wall as your background and you don't get some kid at another table in the background picking his nose... (OK, that never happened, but I like photos of just us without others in the photos).