What is the best method for an emergency takeoff?
Near as I know there are no emergency takeoff procedures and for good reason:  if you do have an emergency, stay on the ground. Period.  As for emergencies which happen during a takeoff roll, this one really isn't covered among them as there really is no emergency regiment to get airborne.  The KLM captain in the Tenerife accident made a series of judgement errors and failure to follow ATC instructions combined with bad weather and a crowded airport which contributed to the accident.  Once he was rolling, the best he could do was just hope the plane would reach Vr and climb over the PanAm jet, which didn't happen.  He panicked at the end with the tail strike, only making things worse.  But at that point he had painted himself into a corner with no escape.