I'm not sure what the technical name is but it's something like child swap,kid switch,parent swap--it's been most helpful to our family kids ages, 9,7,4,1. Some rides are different--ask CM when getting on ride. But generally the whole family waits in line, CM will tell parent and any children not riding where to wait--then when they are done--you switch. Sometimes older kids get benefit of riding 2x and only waiting in line 1x. (they let the second parent bring someone to ride with)!
We generally use the 20 minute rule--if a line is longer than 20 min. we skip it. Usually at some point during the day, it will be under 20 min. Either with fastpass, early in the morning or late at night. Kids just can't stand in line that long.
Snacks are a definate must.
Naps are also critical--wether it be at the hotel or in stroller.
Ziplock baggies--can never have enough--all sizes. (snacks, dirty diapers/clothes, clean/dry clothes, dry autograph books, dry camera, dry diapers)
Rain ponchos--depending on season.