A general rule of thumb is to use between 1/2 to 3/4 cups of corn sugar or other priming sugar per 5 gallons of beer for a moderate level of carbonation. However, it is important to note that adding too much sugar can result in over-carbonation or even bottle explosions. It is recommended to use a priming sugar calculator, which takes into account the specific gravity of the beer and desired level of carbonation, to determine the appropriate amount of sugar to use.