Much depends on the house. Traditional UK family housing with 2 plus stories and fron and back windows are far easier then modern subdivided multi flat buildings.

The older building allowed concentrating on air flow by opening highest widows and drawing curtains that face the mid day sun. While opening lower windows on the low sun side. During the night crated a natural flow of air.

Modern housing means the internal divisions and often lack of non concreted areas. Often prevent cooler air being able to flow. Or existing if the concrete hass 0 shading from the days sun,

Single level can still do it. But much less effective as the temp difference is less. But when the internal layout limits airflow from the high sun to low non sun side. Way harder.

Downstairs fans running overnight while sleeping with upstairs top windows open. Can be a huge difference.

Or just remembering the direction goal of fans. iE removing higher air while pulling in from lower.

It's common for folks to place the fan between them and the window blowing at the bed. This is the worst thing as you are preventing hot air from leaving. Assuming you are not on the lowest floor.