The article is devoted to design and investigation of a set of heuristics intended to optimize the three-dimensional orthogonal packing problem with the multimethod genetic algorithm. The proposed heuristics are based on five rules for selecting objects and seven rules for selecting free spaces of containers. The quality and time effectiveness for all these rules were determined. The probabilities of including these rules into new heuristics are given. The article contains results of computational experiments carried out on the standard instances of the three-dimensional orthogonal bin packing problem.