Food is the second cocktail party essential. There are a lot of great recipes for you to try (see: finger foods, hors d'oeuvres, and/or buffet-style). Try to choose one or two and stick with those. There's no need to serve more than that.
Once you've decided on the food you'd like to serve, it's time to think about how to present it. You have two options: to present foods at their food station, or use butler service. Butler service is a classy touch that involves hiring a person or two to walk around offering trays of yummy finger nibbles to your guests. This method can save you money on food, but you usually lose that savings in what you pay the hired help. Alternately, you can set up a food station—a table or buffet where food is presented—and your guests can help themselves.
For a stress-free cocktail party, don't be a slave to your oven. Choose recipes that can be made and served without having to be constantly warmed. A good host should be spending time with guests, not in the kitchen. The very best cocktail foods are finger foods that require no plate or utensils. They can be skewered or kabobbed with frilly toothpicks or bamboo.
Setting out food on platters is fine, but to add a professional touch, use some sturdy boxes and linens to create different heights. First, place linens of some kind on the table to create a skirt. Then place the different-sized boxes on the table, drape linens over them, and then scrunch the linens all over. Place your platters of food accordingly and add little folded food labels.
If you do not have linens or tablecloths, you can use the paper tablecloths you find at party stores. Just stick with black or white. It's also acceptable to place food on trays all over the room. Don't forget the extras that might be needed, like napkins, plates, or utensils. If you choose to use plastic or paper plates and utensils, buy clear or black.
You can find perfectly fine serving platters, chafing dishes, linens, and lots of other items you will need for your food presentation table at local thrift stores. Try the thrift stores that are in the wealthier neighborhoods first for the best selection. You will be amazed at what you will find. It's a great way to start building an entertaining collection.
Doing the Math
Guests at a cocktail party will eat around six bites of food per hour. In the first hour, people arrive late. The second hour is the peak hour, and in the third hour they are winding down and getting ready to leave.
Although you never can predict exactly how much food will be needed, a good average is about 10 bites per person for the entire party. So take the number of people expected and do the math. Make as much as your budget will allow. Don't worry if you run out in the third hour—it's a sign of a great party.