Go during the cheaper time, January through February (avoid president’s day), May (before school gets out) and Fall. So far my favorite time has been Fall because I love the fall decorations, you can also add on Mickey’s Not So Scary Halloween Party.
If you are trying to squeeze the budget, avoid getting the Disney dining plan and have groceries delivered to your room. If you plan on reserving any character meals, I suggest you sign up for the dining plan and allow the splurge. I have a handful of friends with kids that truly Do. Not. Eat. and the dining plan would be a huge waste. However, with my family I prefer the dining plan because it keeps me from penny pitching throughout the day, thus making my family miserable.
Skip the Park hopper if you have small children. I have never found the idea of running in between parks as fun. Usually, I have the kids rock through Disney in the morning, take a nap and then we go back to watch the fireworks show.
Buy souvenirs before you go to the park. Now, this might sound crazy but believe me, a quick trip to JC Penney’s clearance section will get you everything you need to make your kids happy during the stay. Remind them, every moment shopping is one less minute on a ride, watching a parade or at the pool. My favorite souvenir is buying clothes for the trip and wrapping them up. Every night before bed they get to unwrap their new Disney shirt and then wear it the next day.