Irma, that's the I usually do it but the way I've described can give excellent results .............. or rubbish!

This can work well or be a waste of time though it's worth trying as it's so quick. I often find I have to expose for the sky so the foreground is really dark. I shoot raw images and convert for thw s...

Irma, the reason it's accumulative is you're using the airbrush, turn that off and you'll just get the 2% on each pass