This paper considers some of the pertinent aspects involved in the efficient design of a high voltage, low jitter trigatron switch. The performance of a high voltage triggered switch was initially evaluated. This switch was tested using a 10 stage 1MV Marx generator and a single stage trigger source. The Marx generator and trigger source were synchronized to enable jitter measurements to be carried out. The information gained led to the design of a trigatron switch with enhanced performance. This switch performs with subnanosecond jitter when operated at either a very high voltage or by using a corona pre-ionizer source at voltages up to 500kV. The corona source produces negative ions which have been shown to reduce the jitter in SF6 gaps by minimizing the statistical time lag. The measured jitter varied inversely with breakdown voltage for a given gap spacing and pressure. Extensive electrostatic modelling of the trigatron was carried out to ensure optimal triggering in the final design.