Use Good Seed - You might be tempted to save a few dollars by going down to the local coop to buy your seed. Don’t. You want a blend that has been engineered for food plots. Companies like Biologic and the Whitetail Institute have conducted extensive research on which blends are most palatable to deer. Conversely, local blends are much more likely to contain predominantly red clover and alfalfa, which make great cattle forage, but tend to have more coarse fiber, and thus, are less digestible to deer.
Define the Purpose - What you choose will depend on your intended use. There are two types of plots: feeding and hunting. Feeding plots are designed to meet the year-round dietary needs of deer, keep deer on your property year round, and grow them bigger. Perennials and high-protein annuals are better here. Hunting plots are for attracting deer so you can shoot them. Use fast-growing annuals that are high in carbohydrates.
If you’re not sure which is which, most commercially-available brands will state on the packaging whether they’re designed for spring, summer or fall. You just need to determine your intended use and select the recommended blend.