* Blow one's own trumpet: This is the most common and straightforward idiom for boasting.
* Toot one's own horn: This is another common way to describe boasting.
* Swagger: This word implies a confident, self-assured, and possibly arrogant way of boasting.
* Braggart: This is a noun describing someone who boasts a lot.
* Show off: This is a more general term for someone who wants to impress others with their abilities or possessions.
* Crow about something: This idiom suggests boasting about something you've achieved.
The best idiom to use depends on the context and the tone you want to convey.