How do I tailor a cover letter to a specific job?

Tailor three things: the role and employer details, the examples you choose, and your reason for wanting this job. A tailored letter could only have been written for this one application.

Step by step:

• Read the advert and mark the three or four most important requirements.
• Name the exact job title, the company and any reference number in the opening.
• Choose examples from your experience that match those requirements, and lead with the strongest.
• Add one or two sentences about why this employer appeals to you, based on research.
• Use the advert's key terms where they truthfully describe your experience.
• Address the letter to a named person if you can find one.

Example of a tailored sentence:
"Your advert for a Facilities Coordinator mentions managing contractors across several sites; at Horizon Properties, I schedule and check the work of cleaning, security and maintenance contractors across four residential towers."

Keep the parts that do not change, such as your header and some general background, in a base letter. Then spend your time on the opening, the examples and the motivation paragraph for each job.