Even if a lot of people say that cover letters aren't important during the application process, to most HR managers these letters have some significance to their decisions in choosing potential applicants for the roster.
The cover letter is basically the first page that the boss will browse through when a resume is submitted, giving him or her an idea of how interested you really are in the job position they are offering.
Standards for job applications and employee qualifications have risen up since wages are becoming higher and higher, so usually bosses would narrow down their choices basing on the resumes and documents they receive about the applicant.
Writing an interesting and creative cover letter usually increases your chances of being in that roster of applicants.
It serves as your very first impression to the company, so it has to reflect just how interested and how determined you are in getting that job.
A lot of applicants would usually learn by downloading a cover letter template and using it as a guide to write their own cover letters.
A cover letter template can be very useful since it allow people to pattern it to their own letters basing it one the structure, format, and style.
Unfortunately most people would download a generic cover letter template and use that to submit to the HR managers instead, which not only would show them a hint of laziness but the inability to really think out of the box.
If you want to avoid such assumptions, then use it as a guide and draft your very own cover letters for every job application process you get into.