I'm an acupuncturist, so I normally give myself acupuncture when I start to feel under the weather and the cold/flu goes away immediately. For fever/flu can only recommend ginger and mint tea since that's what most people have in their cabinets. Unless you have some honeysuckle or get to a chinese herb store, which most people can't.
For colds with (no fever) chai tea has a lot of common ingredients for chinese herb cold formulations.
Oh yeah, and drinking a lot of hot water will help with mucus/congestion.