Getting a letter of recommendation when you've been fired for cause is a challenge. However, it's not an insurmountable challenge. If you've been fired as part of a layoff or reorganization, obtaining that letter shouldn't be much of a stumbling block.
No Recommendation, No Problem
Many employers refuse to give any information about an employee's tenure other than to verify the dates of employment and perhaps the title of the job. Check with your human resource department to see what the company policy is. Ask a friend who owns or manages a business to call and verify your employment to see how the company responds. When you're asked why you don't have a recommendation from your previous employer you'll be able to explain it was company policy not to do so.
Go Lower or Higher
The supervisor you had prior to the current one might have no hesitation writing a recommendation for you if she was well satisfied with your work. The next level of management above the boss who fired you might be willing to write a letter if the firing was based on more of a personality issue than a work issue. If you left your previous job in good standing, that company may write a fresh recommendation so you won't need one from the company that fired you. On a side note, they may want to hire you back.
Even if the firing was for cause, ask immediately if a letter can be written that outlines what you did well in that job and doesn't mention why you were fired. Have suggestions of what specifically could be included in the letter. Sometimes the job you were hired for or promoted to doesn't turn out to be the job for you. For example, your strength might be in organization and seeing to details, and the new job called for flexibility and making quick decisions.
What Was the Cause
Getting fired, terminated or laid off are terms used somewhat interchangeably although they do have different meanings. Being laid off doesn't put your work performance in question. Termination could mean either laid off, your job was eliminated during downsizing or you were fired. Draft a letter of recommendation to give to your manager if your job was eliminated through no fault of your own. The draft can be used as guide for the letter and it will save the manager some time.
Ask co-workers, team members and other department managers to give you a recommendation on how you performed at your job on a personal level, not as representatives of the company. Ask customers and vendors you worked closely with for letters. If you spearheaded a charitable campaign or organized a community event, ask the event administrator for a letter of recommendation.
Set Up a Consulting Business
Even if you don't plan on working as an independent consultant as a long-term job, it does give you the opportunity to get recommendations from your clients to use with prospective new employers.