The consideration of a scenery as an idyllic one may vary based on the assessment on each person, but there are certain elements that normally characterise this type of scenes such as impressive landscape views, vastness in the horizon or the sky, harmony between the elements participating in the picture (including animals and humans), and overall a strong connection with a conformity in a group or society with certain ideals or iconic views of a certain reality.
These realities can cover so many aspects, from the idyllic life in the countryside, or in the mountains, to an iconic view of a certain natural environment or landscape associated with a certain region or part of the world.
Generally this type of photographies are very linked to landscape, lifestyle or documentary photography. The same as for other types of photography, this one usually requires a good amount of planning, towards the location that we want to photograph, and a great dose of exploration and observation of the surroundings once we are at the field we aim to photograph.
Contemplation, patience, and observation of the interaction of the people, animals, or weather conditions will play a role to make us decide which angle, perspective and location is the right one.
I deeply recommend for this type of photography to spend time on it, not only just on the technical adjustments of the camera or framing the right composition, but simply observing and enjoying the environment, walking around and interacting with it, as in this process it will come very natural to make the right decisions prior shooting. These decisions may cover from which specific landscape elements we want to keep in the background or in the foreground, which animals or plants we want to use as subjects, and how we want them to appear, as very likely through contemplation and observation we will become good in anticipating how those elements may interact or stay for certain periods.