A good or even perfect resume is straightforward! You should only include the relevant information that benefit your core argument (e.g. Why they should you hire you for the positon). This will make your resume easier to read and presents a more professional and experienced picture of yourself.
If you have skills/ tasks from your past job that are not relevant to your current job search—don’t include them. Put forth the effort in determining your skills and tasks that are most relevant to your current job search, place these points in parts of your CV that are more apt to be read. And lastly, make each paragraph and sections of your CV short, but substantive. Sections should not be more than five lines long, in order to keep your reader inserted and engaged.