Always be ethical in all your actions as a professional in the industry. During your time practicing your penetration testing skills, I'm sure you will have realized that there is a fine line between being a malicious hacker and a penetration tester. The main difference is that the penetration tester obtains legal permission prior to performing any sort of attack and the objective is to help an organization to improve its security posture and decrease the attack surface that an actual hacker might exploit. Being ethical simply means doing the right thing and upholding moral principles.