Of course, employers don't want to receive a boilerplate cover letter. They want you to respect their time by investing your time in creating the unique cover letter. And, of course, since there will be 299 other applicants for this, you resist spending the time putting together a cover letter from scratch.
Well, there's a middle road on this. Here are 5 tips how to make the cover letter sound like a unique creation for that specific opportunity.
Analyze the ad. Usually there are hidden clues in each ad about what the employers really want and how they want you to present yourself.
For example, if the ad is highly detailed, that means they want a process-oriented person. Therefore, you will reconfigure your template to deliver that in content and tone. On the other hand a short help-wanted means the employer is more entrepreneurial and operates in the fly-by-the-seat-of-the-pants way. Cut out all unnecessary verbiage in the pattern. Punch up the tone to be perky.
Insert the keywords. Check out the language used in the help-wanted. Insert those keywords in your pattern. Put them in the subject head of your email.
Add/delete. This particular job involves a lot of research. If that experience in not already in your cover letter, put it in. If it is, add more details. But suppose the job doesn't include any research. Then, delete that portion of your cover letter which presents yourself as an experienced researcher.
Cite name of organization or generic identity. The ad might give the name of the company or the contact person. Mention those several times in your cover letter. If only the generic identity is provided, explicitly cite that. For example, "In a social media startup such as yours ..."
Proofread. With all the changes made, the odds are that there are typos and errors in grammar. So, proofread the revised version of your pattern.
The bottom line on cover letters is that they are the only way we have to make ourselves known to employers. We have to give each our best shot.