The two most important factors affecting almost every aspect of the clotting process are

The two most important factors affecting almost every aspect of the clotting process are : Calcium Ions and Vitamin K. Both Calcium Ions and Vitamin K are needed to synthesize Protein C, an anticoagulant that prevents excessive coagulation after it  occurs. Deficiency of any of these clotting cofactors will cause a lessened ability for blood to coagulate, which can lead to excessive bleeding and hemorrhage.

The skills he need is to practice seeing and hearing