Focus on your exhales and let the inhales take care of themselves, if you focus on inhaling it’s easy to hold your breathe which we don’t want to do.
Breath as calmly and naturally as possible with a rhythmic inhale through the nose and an exhale through the mouth.
When swinging the heavy club, exhale when the club is heaviest and inhale when the club is lightest.
For example during a club mill, exhale when the club is heaviest during the bottom portion of the swing and inhale when the club is lightest when it’s being drawn back towards the body and behind the head.
Some movements require an extra breathe, for example swipes. During the swipe there are two acceleration phases (the upswing and the front cast), at this point of the movement exhale with the exertion. There are also two phases where the club is almost weightless (the downswing and the shoulder cast), at this point inhale.