I often see resumes in my job, or look them over for friends. Here's my general advice. Of course this is all my opinion (especially about style of a resume), and I'm sure there are other valid approaches out there.
The shorter the better
- look at every word and phrase and see if it is adding anything to the story
- if an item was covered in a more recent job, leave it out unless it has a unique point to make
Be results-oriented. Don't describe the initiative, give details of what the return to the business was. NO: "Led restructuring of Accounts Receivable process, redefining roles and eliminating unnecessary process steps." YES: "Restructured Accounts Receivable for a 50% reduction in payment processing time with 15% less staff."
If something was hard, make sure it is clear why it was hard. Was it contentious? Was it technically challenging? Did you do it while budgets were being cut? etc.
Anything more than 10-15 years old has limited value and should be really short
- it is good to have the company name in case a reader knows someone there
- leave in enough to show continuity of work and career growth
- anything that's unique compared to the rest of your career gets more room (e.g. you worked in another industry)
Leave out business buzz words (e.g. "synergy", "re-engineer")
Non-work experience can be highly valuable. Many people do things I find very impressive, such as run for public office, be a leader in the business of their church, serve in the National Guard, etc. Especially for people in big companies, outside activities can show start-up spirit and hands on leadership that is hard to project from a description of one's day job. (Just make sure it doesn't look like you're all about your hobby and don't show up to the office very often!)
I like a couple of personal notes. Not everyone does, but I find they add depth to a person, and often gives me something to make a personal connection with in an interview. "You do triathlons?" "What type of photography do you do?"