blowing/tooting his own horn

Tooting ones own horn, also called blowing their horn, means to be brag or boast about ones self. This cliche is typically used in reference to telling someone not to toot their own horn as bragging is considered being conceited, or thinking very highly of ones self and is often frowned upon. Tooting or blowing your horn can mean you often brag r boast about your talents, skills or other good qualities.