Use 'crunch up' to describe sounds and textures that evoke a vivid sensory experience. Listeners could hear her crunch up the dry leaves underfoot.
Pro Tip 2/3
Action Intensity
'Crunch up' suggests a forceful action, emphasizing the energy put into crumpling or compressing something. He crunched up the empty can in frustration.
Pro Tip 3/3
Destruction
The phrase often implies destruction or transformation of an object's original form. After reading the letter, she crunched it up and threw it away.