The best way to check on your plant for moisture is to stick your finger into the potting medium. If it is moist at the first or second knuckle, put the watering can down.
If it is dry, then give it a good drink, Keeping is consistently moist is a good practice. Every plant has different water needs but the technique is the same for all. Water your plant until water runs the bottom of the pot. Make sure to water all around the pot and not only on one spot. This ensures the whole rootball is well moistened. The key thing is to check every plant individaully to see if it needs water.