If your employer offers a retirement savings plan, such as a 401(k) plan, sign up and contribute all you can. Your taxes will be lower, your company may kick in more, and automatic deductions make it easy. Over time, compound interest and tax deferrals make a big difference in the amount you will accumulate. Find out about your plan. For example, how much would you need to contribute to get the full employer contribution and how long would you need to stay in the plan to get that money.