The Node selection (NS) and variable and direction selection (VDS) heuristics significantly affect the time to find the MIP integer-optimal solution when using branch and bound method. In this thesis, various variable and direction selection methods are tested coupled with the node selection heuristic by Wojtaszek and Chinneck. Rules are developed to select VDS / NS configuration depending on MIP characteristics. Empirical results show a new VDS / NS configuration outperforms the state of the art as well as the VDS / NS configuration found by Wojtaszek and Chinneck. The hypothesis that a feasibility - oriented VDS coupled with a good NS heuristic will provide the fastest MIP solution time is disproved. A new hybrid VDS/NS selection heuristic is developed and shown to provide better results than any individual VDS/NS configuration or the state of the art default configuration.