Disclaimer: this guidance is primarily focused on resume conventions in North America.

What should be on a resume

• Use a simple descriptive filename (Mirabel Madrigal - Resume)
• Your first and last name
• Contact/location info: a professional/normal email (not djdoughboy69@aol.com), a phone number, and location (city, state is fine - full address unnecessary)
• Relevant links: your LinkedIn if it looks decent, your website/blog/portfolio if it's appropriate, done well and relevant, your Twitter if you dare, for tech your GitHub/Kaggle/Dribbble/other social profile showing your work (again, if it looks decent), for online/social-focused fields maybe your Instagram/YouTube/TikTok/OnlyFans (okay probably never that last one)
• Your professional experience (company, title/role, start/end months/years, bullets about your impact/responsibilites/accomplishments) in chronological order with the most recent stuff at the top. If you've been promoted make that clear.
• Objective demonstrations of your positive impact in previous roles (hard numbers best, clear description of results if need be)
• Clear, descriptive, plain language that paints a picture of the context of your past role for the uninformed
• Evidence that you understand the bigger picture/company goals in the way that you describe your past roles & responsibilities
• Your educational experience (school, degree, leadership/major accomplishments)
• Relevant certifications
• A short list of your top (read: not all) skills
• Something that makes you human (our favorite go-to is a single Interests line at the bottom of the resume - the more diverse, intriguing, and specific the better!)
• Also, always submit your resume as a PDF

What might belong on your resume

• A summary. If you are making a career shift OR your experience's relevance to the position(s) you're applying for is non-obvious, a VERY SHORT modest yet descriptive summary is acceptable and probably advised. 2-3 lines, tops. The goal is to quickly frame your narrative for the reader with regards to why you are legitimately interested in the role you're applying for. Not a bad addition for college students seeking internships or recent graduates either. If your background is an obvious fit for the role there's no need to include a summary and you would be better off using the space to add more detail on relevant experience instead.
• Significant volunteer experiences (things you are/were truly into and demonstrated dedication via number of hours, leadership, or impact)
• Your GPA if it was good (3.5+)
• If (and only if) you're still in college or applying for your first job maybe your SAT/ACT scores if they were exceptional. This also might make you look like a douche. Read the proverbial room. Consulting at one of the big places? Hell yeah. The local police force? Probably not.
• Impressive side projects (if non-threatening to whatever employment you're seeking)

What shouldn't be on a resume

• Your full address
• References (if/when companies want 'em they'll ask)
• "References available upon request" - that is assumed and should not be stated
• Typos, inconsistent spacing, misspellings, weird capitalization
• Verb tense abuse (current roles should be in present tense, past roles should be in past tense)
• Flowery jargon that means absolutely nothing
• Cliches
• Opinions about yourself
• Lies or exaggerations
• Speaking in the 3rd person about yourself (this goes for LinkedIn too you weirdos)
• Your picture
• Your age
• Your criminal record
• Salary history or requirements
• Negative comments about your previous employers
• If you have a LinkedIn, anything that is inconsistent between the two professional experience-wise (title, dates). If you have additional older/less relevant work experience that is on your LinkedIn but isn't on your resume that's totally cool.
• Your high school info. Caveat: if you are a current college student applying for internships this is fine and may even be advisable if you have an impressive high school profile (strong academic performance, leadership in extracurriculars, etc).
• Paragraphs or single bullets longer than 3 lines
• Passive language
• Strong political or religious takes (interned for a congressman or hold a position of responsibility in your church? both totally fine)
• Basic computer skills, outdated skills