1. Rider swap - You or someone else from your party stands in line for a ride and when they initially get into that line they tell a cast member at the entrance that they want to do rider swap. The attendant will give you a special slip and then that part of the party waits in line. After they are done riding the ride, they pass you the slip and you get to cut into the Fast Pass line with your child or party that is with you also, even if they just rode with the other person and then you get to ride. This is not available on every ride, but here is the page where you can find the rides that offer this - Disneyworld rides - Disneyland rides on the sidebar there is an option for Features, then click on Rider swap. So nice if you have a baby or if you want to take turns riding a roller coaster and neither of your kids can or want to. My husband and I did this for Tower of Terror and a few other roller coasters on our trip and it was nice to know about!
2. FastPass - Once again this feature in Disneyworld and Disneyland aren't offered on every ride, but usually the most popular rides! Fast Pass is where you use your entry ticket into the parks and (usually) there is a special kiosk to the side of the rides and you insert your ticket and you get a return time to come back and enter into the FastPass line which is considerably shorter wait time. You can have multiple Fastpass tickets at a time, but be warned that if you get a ticket for 6pm that evening and one for 4 pm you won't be able to get another one until you've used one! At Disneyworld my husband got in line for a ride and then I ran with our tickets to Space Mountain to get a FastPass for each of us and the pass was for hours later. They also only put out a certain amount of passes per ride/per day. So choose wisely which pass you want. I also sometimes get a FastPass, wait in line to ride the ride then and also come back to ride again when it's FastPass time. Tower of Terror is a ride that I felt was worth the wait! Plus I love to ride it over and over!
3. Stay at Disney! - The last two times we have gone to DisneyWorld as a couple and as a family we stayed on resort. There are perks! One perk is Extra Hours at the parks sometimes in the mornings you get in early at one park and then that evening might be extra hours at another park. You must be a resort guest, you find the castmember in that park and they scan your guest card and give you a wrist band. Then certain rides, not all, are either open earlier or later depending on when you go. When you stay on resort you have the option of Magical Express which is where they will pick you up from the airport, they get your bags and everything! I'll write more on this! You also don't have to worry about renting a car if you don't plan on leaving the Disney lots. Disneyland has magic mornings and some other perks for using their travel agency. I will say things seem a lot closer and it would be much more convenient to go to the hotel for breaks and to go to the other parks. I can't wait to go to Disneyland!
Of course there is so much more I could talk about, but these are my top three!