Watering too much is often worse than not watering enough. Although you may be tempted to make a habit of watering your plant, you should water when the plant needs it. Different species will require different moisture levels. You should research your particular plant species to see how often and how much you should be watering your indoor plant. You can also download apps that let you know when to water each of your plants. A good rule of thumb is to check the soil before you start to water. If the soil is still damp, you probably don't need to add more water to the soil. However, some plants favor wet conditions more than others. For example, if you watered your elephant ear as much as your cactus, you may end up with more of the first and none of the second.