Lighting:
Most indoor plants need good amount of light. You can provide this through natural lighting in the room of your choice or there must be electric lighting. Darker leaved plants usually don't need as much light as others.
Watering:
A common mistake most people make in indoor gardening is that they tend to over-water the plants, which may lead to rotting roots. Make sure to research the type of plant you have, because each kind of plant varies on their watering needs.
Potting:
Choose good quality and attractive containers for your indoor plants. Make sure that the pot is clean before placing your new plant into it to prevent infection and to encourage healthy growth.
Humidity:
In indoor gardening, humidity is a big issue. The amount of moisture in the air has effect on the growth of the plants. In the mornings, you could spray the plants with water for their much-needed moisture. Make sure the leaves don't get covered in dust.
Fertilisation:
Just like watering, fertilisation depends on the type of plant. If you have managed to supply your indoor garden with the right amount of light, water and humidity, fertilisation may not need much attention. A good indoor fertilizer can be bought from most home depot or hardware stores.