Gene regulation of evolved organisms is marked by a high degree of reliability. In order to further understand this, we investigated the properties of Boolean networks that follow a given reliable trajectory in state space. We consider reliability from two perspectives: According to temporal fluctuations of the update time, and to fluctuations of the expression level (boolean value) due to a temperature parameter. The first reliability criterion allows for the direct creation of sequences of states which is independent of the order in which the nodes are updated (i.e. with maximum fitness), as well as the minimal networks which are capable of realizing them. The second reliability criterion is obtained by maximizing a corresponding fitness function and mutating the underlying network. We explored numerically the topology, the update functions, and the state space structure of these reliable networks. Relevant papers: Noise in random Boolean networks, Tiago P. Peixoto and Barbara Drossel, Phys. Rev. E 79, 036108 Boolean networks with reliable dynamics, Tiago P. Peixoto and Barbara Drossel, arXiv:0905.0925v1