For next year, we're planning on flying indirect, midweek for an odd number of nights. That seems to be the cheapest option for us right now.
Also, not sure where you are in the country, but look at alternative airports to your usual. For example, I have read in the past that sometimes its cheaper to fly from Scotland later in August as the Scottish schools tend to go back earlier than English schools.
Staying off site is the cheaper option for accommodation but choose carefully depending on whether you are having a car or not. The hotels on hotel plaza blvd are a cheaper alternative than on site, but there aren't many restaurants within walking distance, other than those at Disney springs, which generally you will still be paying Disney prices for. We like the hotels on / around Palm Parkway in Lake Buena Vista as there are lots of restaurants nearby, and some of them offer free shuttles to the parks, or the lynx bus can be used.
If you are having a car, remember to factor in parking costs at the theme parks.
Discovery cove has a huge black Friday sale on at the moment, so if you are planning on visiting any of the Sea World parks it might be worth taking a look. Lots of the ticket agents are honouring the discount too.