Here's one that always works for me when I feel symptoms coming on.
1. Take zinc. Don't overdo it. Too much zinc can have bad side effects like acne.
2. Drink hot liquid. As hot as you can stand. As much as you can. This kills the germs in your throat.
3. In between sips of hot liquid, occasionally drink cold water (distilled if possible.) This washes the dying bacteria down into the stomach where they can't survive.
If you do this when the symptoms start, you'll have great success. But it's also helpful at any point in the cold if you don't head it off at the beginning.