Let others do your bragging for you. If you are worth bragging about, others will brag about you. Never brag about yourself, your achievements, or your accolades and accomplishments. Doing so only reveals and illuminates your own insecurities about yourself.
Be humble. Let humility be what marks your life and character. It will often be tempting to tell others of what you have done, or something significant that you have achieved, or some program for which you've been selected out of a larger pool, but resist that temptation. Anybody can brag about their own accomplishments. But, it takes a strong, secure, unique person to let others do your bragging for you. If your accomplishment is actually noteworthy and worth talking about and celebrating, others will do that and you will not have to. Don't pursue heights and objectives for the purpose of being celebrated for achieving them. Pursue them for what you learn in the process. The journey itself is far more beneficial and rewarding than the achievement, for the achievement would be meaningless without the journey to get there. You enjoy the journey and gleam as much wisdom as you can, and let others do the celebrating on your behalf.