The pilot reports that he intended to conduct a practice flight to rehearse for an upcoming air display. His intention was to activate the aircraft's display smoke system on the runway threshold and complete a tight turn through 360 degrees, prior to commencing the take-off roll. This would be followed by a steep climb out to position the aircraft for commencement of the airborne display routine. A gusting crosswind was blowing across the runway being used for departure. The pilot indicates that after turning left through approximately 90 degrees, the aircraft accelerated sideways across the grass and the right main wheel began to skip. The pilot was unable to maintain control of the aircraft and the right wheel appeared to dig into the grass runway surface. The aircraft was observed to nose over, before toppling onto its back. The pilot was not injured. The pilot states that the loss of control was most likely a combination of the gusting crosswind conditions and the right main wheel digging into the soft runway surface.