Hiring managers reading through dozens of applications develop a fast sense for which cover letters were actually written for this job and which were copy-pasted from a template with the company name swapped in. That distinction, more than polish or word choice, decides whether someone keeps reading.
Skip the generic opening entirely
"I am writing to apply for the position of..." tells the reader nothing they don't already know from the subject line. Open instead with something specific — why this company, why this role, or a concrete result relevant to the job.
Mirror the job posting's actual language
If the posting emphasizes "cross-team collaboration," use language that reflects that directly rather than a synonym. It signals you read the posting carefully rather than sending the same letter to twenty different companies.
One concrete example beats three vague claims
"I have strong communication skills" is forgettable. "I rewrote our onboarding docs after new hires kept missing the same three steps, cutting first-week support tickets in half" is specific enough to actually stick in a reader's memory.
Keep it shorter than feels comfortable
Three to four paragraphs is usually enough — a cover letter that repeats the entire CV in prose form doesn't add value, it just delays the reader from opening the actual CV where the detail belongs.
End with something specific, not generic
"I'd welcome the chance to discuss how my experience with X could help with Y" reads far better than a generic "I look forward to hearing from you," because it references the actual role rather than closing out any letter you might send anywhere.