It’s hard to promote yourself in person, let alone on paper, without sounding like a narcissist. But it’s necessary, and there are ways to do it that won’t make you sound like a braggart.
It is extremely important to use quantitative metrics to describe your achievements to make you stand out. Hiring managers want to know that you increased satisfaction, reduced costs or improved efficiency (and want to see numbers to prove it). But those are your claims the hiring manger must decide to accept or not; how about words from the mouths of your colleagues? This is why special recognition needs to be on your résumé too. Otherwise, how will a hiring manager know that others think you’re a star employee?