Winning the lottery is a dream come true for most Americans. But it can end up being a nightmare for some who aren't prepared for the changes in lifestyle and relationships that come with that winning ticket. If you have won even a modest sum, it's vital that you plan ahead to avoid the challenges or at least navigate them wisely. And that planning starts before you even pick up the check. Here are five key things to do before accepting any large prize.

Sign the Ticket. Generally, lottery tickets are considered "bearer instruments." This means that whomever is holding the ticket may be able to claim the prize. So, be sure to identify it as yours by signing it while it's in your possession. It may also be smart to place the ticket in a safety deposit box or other secure location.

Meet with a Tax Accountant. Paying the right taxes, minimizing your tax obligation, and putting the money aside are some of the most important things you will do with your money at the beginning. Get a handle on what you will need to pay (above and beyond any taxes withheld by the lottery agency), and how you can reduce that amount through things such as retirement-account contributions, HSA contributions, deferred compensation, or charitable donations before you receive any checks.

Do Not Start on Your Wish List. Even those who don't win the lottery often find themselves dreaming about how they would spend the money. But when you realize that you've actually won, it's better not to engage in wholesale dream-spending for a while. Why? Because sudden changes in their lives may lead people to make ill-advised decisions and large adjustments. Like anyone who experiences a life-changing event—such as divorce or the death of a loved one—it's best to wait up to a year before making any large spending decisions. Avoiding sudden spending changes will also help you maintain your anonymity after receiving the money.

Work with a Financial Planner. Instead of dreaming about buying a boat, a car, or an around-the-world cruise ticket, set up a meeting with a financial or investment planner, such as one from Family Financial Partners. This objective third party can help you formulate a plan for meeting better goals—like preparing for retirement, paying for college, starting a business, and giving to charity. Don't worry, though: you can (and should) plan to indulge yourself a little as well.

Organize All Your Debts. Preparing for receiving your money should also include tallying up your debts and obligations so you can pay them off first. Non-deductible debt (like credit-card debt), student loans, vehicle loans, and personal loans are generally things you will want to get rid of first. Talk with your tax accountant and financial planner about whether it's best to pay off your mortgage or continue to deduct the interest. But, by organizing your financial obligations early, you will be ready to spend the money wisely once you receive it.

By following these five steps before you arrange to pick up your lottery winnings, you can help ensure a smooth transition and spend the money in ways that will improve your life rather than taking it on any unwanted paths.