Find a knowledgeable, ruthless person to edit your style and format. Find someone with experience in your area of interest to edit the content. Target which career strengths you plan to develop. Work your plan and update your resume. If you don't know where you are going, you will probably wind up somewhere else.
Address cover letters to a particular person.
When in doubt, send it to the head of the department for which you want to work. Get the recipient's correct title and double check name spelling. This is easy and it is important. Pitch your cover letter directly to the company for which you want to work. You can use some boiler plate, but you must convey to the reader that you know something of the company and that you have something to offer specifically to them.