The best thing is rest, sleep, and plenty of liquids - there aren't really any instant cures for the cold. But! If you're in the mood for some placebo magic, here are some folk favourites:

-Incredibly Disgusting Cough Remedy (anecdotal evidence only)
-Vitamin C (minor, minor correlation shown, and only with extremely large doses, which in turn can put your kidneys at risk)
-Echinacea (anecdotal evidence only)
-Nasal Decongestants (effective in short term, but actually aggravate and cause symptoms with medium to long term use)
-Buckley's (effective symptom relief, but BLLEHAHHHH)