Include measurable accomplishments such as “increased revenue by 25%” as well as responsibilities. It is easy to get carried away describing your work experience or responsibilities, but keeping it short is crucial. Once you get an interview, you will be expected to go into deeper detail.
There is not one resume format that works for everyone. There might not even be only one resume format for you and it could benefit you to have multiple formats of your resume available. For example, if you’re applying for a job and you don’t know whether your resume will be submitted through ATS, submit both a chronological resume and use a functional resume for your in person interview.