In a self-defence situation – don’t give your brain too many choices to make, because the effects of adrenaline greatly reduce the ability to decide which technique to use. To be effective in a high-pressure situation, whether it is in self-defence or a martial arts competition, our rule of keeping it simple must first be applied in training.
In martial arts there is a syllabus in place which has a twofold effect: (1) basic techniques that are taught at the beginning will establish; footwork, position and other traits that are necessary to perform the more difficult techniques later, and (2) because these techniques are simple after a while, they become the most reliable under pressure. The latter explains why basics should be taught all through your martial arts journey.
The difference between Black Belts and students can be seen in there basics. It is not necessarily in the technique, but in the level of speed, power, timing and tactical application of those techniques. The success lies in the repetition of good technique under pressure, using the skills acquired while seeking perfection.
Keep it simple and reliable.