Overload Principle: To increase muscle strength you must place a heavier load/weight on the muscle than it is typically used to. The amount of weight depends on the individual's abilities.
Principle of Individuality: Everyone's bodies are unique and have individual needs. It is important to set up a resistance training program with your individual needs and abilities in mind.
Avoid training the same muscle groups on consecutive days.
A balanced training program includes all four regions of the body when possible.