You need to restore your electrolyte balance by drinking a home made remedy made with water, juice of 1 lemon, 1tsp honey and 1/2 tsp sea salt. As alternative, a glass of tomato juice with a pinch of salt could work, too. In my home country people also drink brine left from gerkins because it's high in salt (sodium and potassium to restore electrolyte balance), it's water-based for hydration and it contains herbs such as dill that helps to calm digestion.
Fresh grapefruit juice may provide extra support for the liver and reduce severity of a hangover.
Drinking a little extra virgin olive oil may also be helpful.
To restore levels of glycogen that become depleted by alcohol, you should eat a mixture of dried fruits and raw nuts or simply have 1-2 fruit&nut or muesli bars.
Ginger tea is good if you are experiencing tummy troubles caused by excess of alcohol. You can use my recipe to make tea at home. I wouldn't rely on shop-bought ginger teas in this case.
http://optimumnutrition4u.wordpress.com/2010/10/29/ginger-tea-delicious-goodness-in-a-cup/Other nutritional remedies may include bananas (full of potassium for electrolyte balance), milkshake made with honey to calm the stomach (here's a recipe, don't go to buy fast-food rubbish, please
http://optimumnutrition4u.wordpress.com/2010/11/05/honey-vanilla-smoothie/), vegetable broth made with carrots, celery, cabbages and herbs.
Take vitamin C supplement
Avoid sugar, anything containing glucose (such as sports drinks), caffeine (coffee, tea). Drink plenty of water to stay hydrated and rid your system of toxins asap.