Thus, at this crucial moment, less is more. It is possible to have too much Vegemite. It is almost impossible to have too little, if the toast is of good quality and the butter generously spread. This is the error repeated again and again by the uninitiated. Vegemite should be flecked onto the surface of the toast rather than pasted.
Timing is also important.
That is a matter of taste. I prefer hot, and so don't toast more than two pieces at a time. But if the Vegemite and butter have been applied with a level of Zen it should not matter. Most Australians understand this instinctively. Most foreigners don't understand this instinctively.