Luckily, as long as you have honest intentions and reasonable bookkeeping skills, it's hard to go wrong when you run a sweepstakes. Simple chance lotteries can make good fundraisers for charity, or promotions for a small business or event. The most important thing to keep in mind is to make sure everyone understands the rules of the game.
Decide what the prize will be. Common prizes include all the money that is collected from ticket sales (for purely promotional or entertainment sweepstakes) or a percentage of the money collected if the rest is being used as a fundraiser. However, other prizes can also be offered, like vacations, cars, gift certificates, and so forth.
Decide how tickets will be distributed. For example, everyone who attends a certain event might get one free entry, or anyone might be allowed to purchase as many tickets as they like. Decide on the price of tickets, if they will be sold, and make sure to tell people what the money collected will be used for.
Have every entrant fill out a ticket or matching slip of paper with her name and contact information. If anyone gets multiple entries, she should fill out multiple slips.
Be consistent in the way that you fold the slips, for fairness in the selection process. One way to make this easier is to have volunteers fill out the slips themselves, or help participants do it.
Mix the entry slips together well and have a volunteer draw one, in public if possible.
Contact the winner or winners, and distribute the prizes.
Rather than drawing slips of paper, you can use a computer program to make a random selection. You could do this by assigning every entry a number and using a random number generator, or you could use a sweepstakes program that allows you to enter participant information and select a winner directly.
While most small-scale party or fundraiser sweepstakes operate under the table without incident, there are strict rules in many locations about games of chance. Keep this in mind particularly if you're considering running a large-scale or online sweepstakes, and research the regulations in your area.