rolf wroteJust don't clean your sensor. Don't tilt it upwards, protect it, etc.
I have swabs and liquid that I used on my old camera. I put my finger on the sensor (long story). For some reasons I could never get it totally clean, there was a smudge, I think the liquid is not very good.
With my new camera I'm not touching the sensor, just blowing air on it if anything. It has an ultrasonic self-clean function as well.
Keep your camera stashed in a clean place (closed cabinet, wardrobe, etc.). Don't let it lying around on your table, etc. when you are not using it.
Oh yeah I can indicate the place where I got the swabs. They weren't cheap either.
I can get swabs from aliexpress but I never tried them, I am too afraid to put too much liquid