Following are the tips to promote yourself using the cover letter:
Successful salesmen know the names their customers. Like one of them, you should address a cover letter to a particular individual. If the job posting doesn't mention as to whom should be contacted, don't hesitate to ring up the company and get the name of the hiring manager. Be sure of the spelling and the gender of the person whom you would be contacting. Take all these precautions so that your letter goes to the right person. This effort demonstrates your motivation and resourcefulness. Avoid using salutations like "Dear Sir" and "To whom it may concern".
Highlight skill set
While writing the cover letter you should read carefully the job positing and requirements and target your sales pitch accordingly. Highlight your skill set, experience and qualifications in tune with the job needs.
As hiring managers wade through a piles of applications, they don't have time to go through every application in detail. So you have to catch the attention of hiring mangers with your clear, concise and compelling cover letter. Your cover letter should highlight your top attributes succinctly and explain why the job interests you. Then seek an interview and say thank you. That's it, nothing more.
Be honest and truthful. You should not follow the footsteps of advertisers and sales persons who make tall claims about their products and land in troubles. Your resume or the cover letter should not lie and hide anything. Even after landing the job, the lies and misrepresentations haunt you throughout the career. Don't make any boasting claims; be specific about your achievements with proof.