One of the most effective ways is to drink plenty of water because, in this way, alcohol concentration in the body is diluted. Although water consumption does not increase the rate of alcohol breakdown, the concentration of alcohol in the blood becomes lower. Furthermore, the person will feel less drunk and the breath-test using breathalyzer will show lower percentage of alcohol in your breath.

A standard drink is a unit of measurement for determining the amount of alcohol in a drink used in US, Australia, Canada, Mexico and other countries. For example, in the United States and Mexico a standard drink contains 14 g or around 17.7 ml (0.6 oz) of pure alcohol. Number of standard drinks can be calculated by multiplying the volume of the drink (in ml) by its percentage ABV, and dividing by (100 multiplied by ml in a standard drink). For example, 500 ml 5% (ABV) beer in US contains 1.4 standard drinks, 750 ml 12% wine 5.1 and bottle of vodka (500 ml) 40% 13.3 standard drinks.

Source: who.int

Unit of alcohol concept is mostly used in UK and other European countries but has the same purpose as a standard drink. According to the World Health Organization, a unit of alcohol contains 8 g or 10 ml (1 cl) of pure alcohol and can be determined by multiplying the volume of the drink (in ml) by its percentage ABV, and dividing by 1000. For example, 500 ml 5% (ABV) beer contains 2 units of alcohol, 750 ml 12% wine 7 units and bottle of vodka (500 ml) 40% 16 units.

Source: drinkaware.co.uk