It is boring but the best way to cure a hangover is by not drinking too much in the first place.
Actually, the best way to cure a hangover is the hair of the dog that bit you. Hangovers are caused by the liver enzyme alcohol dehydrogenase metabolising the small amount of impurities within any alcoholic drink such as methanol into toxic metabolites such as formaldehyde. Ethanol itself has a much higher affinity for the enzyme and gets metabolised more quickly. Thus, drinking a small amount of alcohol again in the morning slows down the metabolism of the impurities and stops you feeling so lousy. That's the theory anyway.
QDM