Ask about their care routine, and set expectations. Depending on your friend's expectations, your plant-sitting gig might include not just watering, but also misting the plants, trimming away any dead pieces, wiping their leaves to keep away dust or pests, or even singing or talking to them.

In general, houseplants' potting soil should be kept moist, but not wet. They normally need watering once or twice a week in the spring and summer, but less in the autumn and winter. However, depending on the type of houseplant, this is not always the case.

Sufficient light is important to growing healthy plants. Select a plant with requirements that match the light environment in your home or office. Supplemental lighting can make up for a lack of natural sunlight. There are many types of artificial lights in different styles and sizes to fit your needs and budget.