When is it better to do simple stretching before or after a workout?

Lately, I come to the gym early in the morning on an empty stomach.

I am exercising while working out.

I'm doing a full-body Tabata home workout before my regular workout.

I'm too busy to do cool-down stretches after my workout. As for stretching, should I do it before or after?

When should I do it for best results?

Is it more effective to do it both before and after exercise?