Give yourself enough time.
Your first reading will only acquaint you with the problem situation. Your initial reaction may very well be 'there are really a lot of facts here.' Your task, then, is to separate the relevant from the irrelevant, and that takes time.
Allow yourself at least one full day from the time you first read the case until you begin a serious analysis. During this time, think about the case as you take a shower or walk across the campus. Consider alternative problems and solutions. Ask yourself 'if I could do only one thing, would that take care of most of the problems that the firm faces?' This time for thinking through the case is the key to the solution process. Do not cut it short.