(1) A brief introduction about yourself
(2) Give the hirer enough confidence to read further
(3) Provide a call to action as to what you’d want to be done further – fixing an interview etc
Secondly, it is imperative as well as logical to establish your expertise in the cover letter. Talk about your skills and show why & how you can be a good fit for the job. You can also mention how enthusiastic you are about the job position and how you can fit the corporate culture perfectly.
Last but not the least, it is absolutely necessary never to write the same letter to another company. This can prove to be a greater waste of time on your part than the employers.
In fact, writing a cover letter after doing your research and customizing it to fit the specific company can be the spark that gets the fire going. It is always a better idea to write bespoke cover letters to a select few companies (and wait for their response) than to write cover letters “in bulk” as they will hardly evoke a response.
Thirdly, it is very important to tailor-make your cover letter as per the job. This means you will have to do some research on the company, address the letter to the concerned person (most preferably include their name) . This research can be easily and quickly done on the web.