Orchids are members of a genus with thousands of species, but only a few of these are common as indoor plants: most often the phalaenopsis, dendrobium or cambria varieties. These plants are of tropical origin, and need bright and wet locations. You should place them in the brightest area of the house, while avoiding places where they will be struck by direct sunlight for excessively long periods. A place near a window is best, but somewhere where the plant does not feel changes in temperature caused by air coming from the window. Shelves or raised furniture are often chosen for orchids, as this is a way for them to get a good amount of light, at the same time exploiting the warmer air present in the upper parts of rooms. The average temperature in which to grow an orchid is around 15-18°C, so remember to always place them somewhere covered by domestic heating during the winter months. In the wild, these plants enjoy the humidity of tropical forests, so you should spray the foliage frequently, but avoiding the flowers, to counteract the dry air present in our homes. Watering should be very frequent, but avoiding excessive quantities. You should water every week, to keep the growing medium constantly damp, but not soaked with water.
The best way to water orchids is with the immersion vessel technique: we put the orchid’s pot in a bowl and fill it to the brim with water at room temperature; when the upper part of the substrate is damp, take the vessel out of the water and let it drain for a few minutes before putting it back in its place in the pot holder. Every 20-25 days you should add a very small quantity of fertilizer specifically made for orchids to the irrigating water, avoiding excess fertilizer, as this can lead to desiccation of most of the plant's roots.