General advice
A balanced room climate is crucial for the longevity of wood, leather and upholstery. Ideally, the humidity should be 50-60% and the room temperature around 20 °C. These values prevent wood from shrinking and swelling as well as cracking. Of course, it is not always possible to maintain such conditions in everyday life - in winter the air is often dry due to heating, in spring fresh air brings moisture into the house. Natural materials react to such fluctuations - this is completely normal. Think about your furniture when airing and heating.
Avoid direct sunlight: UV light can fade and damage wood, paintwork, fabrics and leather. If possible, do not place furniture in direct sunlight. Use curtains or sun blinds during the day to prevent damage. In the first few weeks after moving in, do not place any objects permanently on new furniture to avoid permanent shadows or marks - especially on sensitive softwoods.
Also make sure there is sufficient distance from radiators or other sources of heat and cold to avoid material stress. And very important: always test cleaning and care products on an inconspicuous area first.