1. Retirement savings accounts
A well-funded 401(k) or IRA can be a retiree's best friend. The only catch is that if you want to rely on your retirement savings account as a major source of income, you have to regularly save significant amounts during your working years. Distributions from tax-deferred savings accounts will be taxed, but distributions from Roth accounts are tax-free.
If at any time during your career you worked for an employer long enough to vest in the company pension (which typically happens after about five years), you may be able to claim pension benefits. A quick search on the PBGC website can help you turn up any unclaimed pensions under your name. Of course, if you only worked for the company in question for a few years, your pension check will be pretty small -- but why throw away free money?
3. Home equity
About 18% of retirees use equity from their homes to help finance their retirement, according to a Gallup poll. The surest (but typically most expensive) way to use home equity as an income source is to take out a reverse mortgage on your home, which will guarantee you a set payment for as long as you live in the house. Other options include downsizing to a smaller residence or taking out a home equity loan or line of credit to provide short-term income.
4. Part-time work
While the traditional idea of retirement meant doing no work at all, these days retirees are often turning to a part-time or side job for extra income. Ongoing work can also give retirees a feeling of satisfaction and accomplishment. Of course, these psychological benefits require a job that's interesting and fulfilling. Perhaps when you retire you can keep your existing job but convert to a part-time schedule. Another enjoyable option would be to turn one of your hobbies or interests into a side gig.