Feedback
fiddle away
Waste time
fiddle around
Waste time doing silly things, or unsuccessful things
Make small movements with your hands
fiddle about
Waste time doing silly things, or doing things unsuccessfully
fiddle with
To manipulate an object, especially in a nervous or restless manner.
To adjust the position, as of an electronic device, in order to provide better reception or signal.
To manipulate in order to gain something for oneself.