Calathea like bright, indirect light. Best placed around a metre away from a window that receives a good couple of hours of light. Be careful the plant isn't exposed to direct sun as its leaves can be scorched.
They prefer higher humidity so pop in a bathroom, next to a humidifier, or mist every day. Soil should be moist a couple of centimetres below the surface. Water less in winter. Be careful with feeding as some plant food can burn a calathea's roots.
Calathea enjoy slightly warmer household temperatures. Best between 15ºc - 23ºc.