blow one's own horn/trumpet, to

blow one's own horn

 and toot one's own horn
Fig. to brag. Gary sure likes to toot his own horn. "I hate to blow my own horn," said Bill, "but I am always right."
See also: blow, horn, own

blow one's own horn/trumpet, to

To brag about one’s own accomplishments or ability, to promote oneself. The term originated in Roman times, and was translated into English early on. “I will sound the trumpet of mine own merits,” wrote Abraham Fleming in 1576. It was a cliché by the mid-nineteenth century, according to Eric Partridge, and gave rise to one of W. S. Gilbert’s numerous puns (“The fellow is blowing his own strumpet,” he said of a manager who was bragging about his actress-mistress).
See also: blow, horn, own