The basic low ground effect takeoff is like getting a free ride. The airplane will accelerate much faster level in low ground effect and the wing will produce sufficient lift to fly in low ground effect long before producing enough lift to fly out of ground effect. This makes it possible to get the beast off the ground, where it doesn't want to be, and into the air, where it accelerates faster, efficiently. And, outside of contest standards, it can be done easily.
If we pull the stick all the way back from the beginning of the takeoff roll, the nose wheel will come off as soon as possible. We use dynamic proactive elevator now to keep it just off or light. In this nose high pitch attitude, the mains will come off as soon as the airplane will fly in low (not high) ground effect. We use dynamic proactive elevator now to stay in low ground effect. Elevator trim should be adjusted to suit (not arbitrarily nose up) before takeoff.
Should the engine fail, it is a much easier to solve situation if we have stayed in low ground effect until sufficient airspeed for maneuvering effectively has been developed. Now we may spend only as much airspeed for altitude as practicable to zoom up wings level and see what is available. Next we turn at whatever bank is necessary to make the LZ anywhere in the near hemisphere. This turn must have no back pressure, however. We just let the nose go down naturally and around quickly (lots of rudder as needed) onto a directed course to the LZ. Expect to be high and fast requiring, usually, full flaps and full slip.
If good maneuvering speed has been developed in low ground effect, this six second flight is sustainable without power.