Before writing a Cover Letter one must know some techniques used by professionals for writing a cover letter :

Customize for the specific job:

Customize your cover letter for each job application by highlighting how your skills and experience match the specific requirements of the job.

Show Enthusiasm:

Express your genuine interest in the company and the position. Let the employer know why you’re excited about the opportunity and how you can contribute.

Keep It Clear and Concise:

Write in a straightforward and easy to read style. Focus on the key points and avoid long paragraphs to make sure your cover letter is engaging and to the point

Hire an expert:

If you are still having troubles writing your own cover letter then hire hiring an expert Cover Letter Writer can be the best option as they use their experience to write an eye catchy letter.