You should have a standard resume and cover letter that you can use at a moment’s notice, so if you meet someone you can provide it, or you can send it out immediately if there is a quick turn-around time. However, if you have time, you should tailor your standard resume to meet the advertised position. For example, if the position is for a civil engineer with a municipality and you have only worked for engineering consulting firms, then indicate in the resume the number of municipal projects you completed as a consultant and describe some of those projects in your cover letter. Your cover letter should also be tailored to use some of the words in the advertisement or recruitment brochure so they know you have done some research about the position or company.
Sometimes adding another page that addresses the specific position—that’s called a tailored resume—may be helpful. For example, when I applied for a Risk Management Position, I created a tailored resume that highlighted all the risk management projects I had completed during my career. They were not tied to a specific job, but listed diverse risk management projects. My resume already indicated that I was a certified risk manager and had the function of Risk Manager in a few positions, but did not go into detail about my risk management responsibilities. The tailored resume provided that extra information.