After drinking alcoholic bevelages, your body gets depleted with vitamin B, potassium, magnesium, and other vitamin/minerals, as these nutrients are used in liver to decompose alcohol. So I have been eating fruits at the end of drinking session with friends. Though fruits are suggested as one of the best remedies to cure hangovers, most people try fruits after they start to have a sympton of hangover (e.g., in the following morning). I found that eating fruits immediately after the drinking session works better, and I often do not feel any affect of alcohol when I go to bed such as insomnia or when I wake up next morning.
Tonight we ordered a large fruit plate to share. It's natural and works better than Tylenol or other pills! Even having a fruit juice or banana helps a lot, so try a bit piece of fruit to finish your next drinking session.
P.S. (on Thu 21 Aug 2014): A few days ago, NPR broadcast an interesting talk show about How to Cure Hangovers: