Why are we asking?

The first 10 years of training are hard, the next ten years even harder. And after that it starts to become joyful...

Harada Roshi

I am not quite sure what you mean by "controlling your breath". If you mean to align your breathing, the breath aligns itself, it is not you doing it. Try to imagine that your body is like an empty pipe- The exhalation passes through an empty pipe like the wind blowing through. When you let the breath flow out in this way, the place below your navel becomes flat. When you cannot exhale any further, let the inhalation follow naturally, entrusting to natural inhalation with a wide feeling.