If you have a camera with interchangeable lenses it’s almost impossible to avoid getting dust on your sensor
To reduce the amount of dust that the sensor collects:
- Never store the camera whithout a lens.
- Minimize the number of times you change lenses and minimize the amount of time the lens is off the camera.
- When you change lenses, make sure the body of the camera is pointed down and the camera is turned off.
- Try not to change lenses in dirty environments.