If you live in a hot climate or you are concerned about how much water you need to use to water your plants, there are a couple tricks you can use to help your plants retain moisture so you do not need to water them as frequently or as much.
In each of your containers, simply place a layer of wood chips or pebbles on top of the soil to help retain the water. This also allows the water to penetrate the layer to get to the soil without any problems.
Beware of using glass rocks or beads, which are often used to make indoor plants more decorative. While pretty, they can actually cause the plants to need more water, since the glass rocks can intensify the heat from the sun (think of a magnifying glass in the sun)