If you live in areas where you experience hard frosts prune later end of July to the beginning of August, pruning can stimulate leaf growth which could be damaged by frosts. Make sure to have well sharpened secateurs to prevent damage to the bush. Remove all wind damaged, insect damaged and dead stems first, also any stems that are crossing over each other through the middle of bush. Prune about 1/3 to 1/2 off the height off the bush, the angle of the cut should be approximatley 45 degress, try to cut to an outside facing bud, new growth will grow up and outwards creating an open airy bush.