Watch for changes in files:

sudo apt-get install inotify-tools

inotifywait -e modify,create,delete,move -r -m /path/to/watch

To do something with the result, the following could be used

inotifywait -e modify,create,delete,move -r -m | while read line; do something_with $line; done 

Watch for dconf changes:

dconf watch /