Sort By Relevance (Ordering Matters)
This one is easy, but often missed. Your resume sections should be most relevant to least relevant, no exceptions.
What does this mean?
If you are a recent bootcamp grad, you likely don't have an education section that is very relevant to being a software engineer-- so put it at the bottom. However, you've just been coding at a bootcamp for the last 3 months, so you'll probably have tons of projects and code samples-- stick this as high up as possible!
Recruiters typically spend 6-10 seconds on your resume, and you can bet they're going from top-down. Use this to your advantage, and place the important stuff higher.
This also means that for large gaps in roles, you'll want to tailor your explanation to the role. If it was due to unemployment, list any open source or personal work done during that time period to demonstrate you continued to hone your skills.