Integrity, honesty, reliability, and loyalty are the easy ways to describe 

trustworthiness. Integrity is believing in yourself and standing up for what you believe in. 
Honesty can be described as telling nothing but the truth at all times and being exceptionally straightforward. Reliability is being on time, following through with what you say you will do, and being dependable. A deep sense of duty yourself intellectually and emotionally to a course of action or a person is a loyal individual. Being reliable, honest, loyal, and having integrity will boost your self morale, while making you appear a person of high quality. 
Being earnest, direct and open with the truth, being honest with yourself, and holding yourself accountable for your actions can help keep you out of trouble. Doing what you say you would do at all times is a good way for others to trust you. Paying off debts before they are due is being accountable. Return what you borrow in a timely manner and in an improved condition is an amazing way to live. Then people will have more respect for you.

A trustworthy person will be dependable and honest with you. They will not lie, steal, cheat, lose devotion in something, or turn their back on you over trivial matters. Being on time for meetings and appointments is a major part of trust. Doing all of these things can build an excellent reputation for yourself, and people will admire you. Trustworthiness is something all employers expect in potential employees. A trustworthy person is a valuable and reliable person.