Consider the spectrum of ages. While it's great to relive your carefree days of higher education, time has now passed. You're older now, act like it. The Homecoming party games should not be focused on beer pong, flip cups or three man. Take into consideration that Homecoming gathers people from many generations. So find games that will suit all of them.
Keep it simple. Don't make the games too complicated. The point of a Homecoming is to catch up with the people you haven't seen in a number of years. The games should be festive, fun, interactive, and not require a lot of objects in order to play.
Plan a schedule. There's nothing worse than having too much or too little to do at a Homecoming Party. If your class was tiny, say 100 people, then one game will probably suffice for the evening. However, if your class had 3000 people, then you have a bigger job. Have games running throughout the evening. Announce the games that are happening and let former classmates come to you when they are ready to play. Almost as if you were at a carnival and people mosey about and choose what they are doing when.
Offer prizes! Nothing gets people motivated like giving away prizes! Visit local businesses and ask for donations or use extra money from ticket sales to go out and buy some really neat stuff. The level of participation will be much greater.
Pick games. Again make sure they are appropriate for multi-generations. Some ideas are the following: Clothes pin relay. This is a relay race where teams try to place clothes pins in a cup by holding it between knees. A Frozen T-shirt contest. T-Shirts are soaked, folded and frozen overnight. Then teams try and separate them and put them on. First team to have them on wins! These are just a couple of ideas. For many, many more visit partygamecentral.com or party411.com. Congratulations, you have learned how to plan Homecoming party games!