Avoid casting too wide a net by applying for every possible job within your expertise
Invest the extra effort needed to tailor your resume and – especially – the cover letter to the specific job. Leverage the insights from point #1 to showcase your suitability. The cover letter in particular should be crafted to impress the reader as to why you’re so well suited for the job and why you’d especially like to work for that company.
Aim for a resume length of 1-3 pages, particularly if you have 10 years of experience or less. Don’t pad your resume with material that’s not very pertinent (e.g., your high school summer job scooping ice cream). Keep in mind that a resume stuffed with material of little or no interest to a hiring manager is likely to be discarded because it looks like too much work to find the gold nuggets in a big pile of sand and gravel. Short but sweet is more likely to be a winner.
Scrutinize your spelling and grammar. Keep an eye out for typos too. A sloppy resume or letter is likely to suggest a level of carelessness that might make you unsuitable for the job. Ask for proofreading assistance from a friend, colleague, spouse, or, preferably, a recruiter.