Some newer jets have takeoff configuration warning systems that let you know if you have missed anything, like having landing flaps in before takeoff. Even so, smart jet pilots do a quick check right before takeoff of all the things that might kill them if missed before beginning the takeoff roll. The systems you would check vary from airplane to airplane and are dependent on what systems the airplanes has. But the most usual suspects are flaps, trims, speed brakes and spoilers. A quick check of the engine and fuel gauges makes sense, too, not to mention verifying that no warning or caution lights are illuminated.