Self-promotion isn’t bragging if every word is true and useful. Say what you did, plainly.

The discomfort around describing your own work usually comes from confusing two different things. Bragging inflates or invents, and it exists to make the listener think less of themselves. A plain account of what you did and what came of it is information, often the information someone needs in order to give you something.

Write one sentence about a recent piece of work using only facts: what you made, what it achieved, who it was for. No adjectives. Read it aloud. Stripped of decoration it will sound far less immodest than you feared, and far more useful.