As a verb:
* The child scribbled a picture of a monster on the paper.
* She scribbled down a few notes during the meeting.
* He scribbled a quick message on the back of a napkin.
* I scribbled a note to myself on the back of my hand.
As a noun:
* His handwriting was just a scribble.
* The note was covered in scribbles.
* I couldn't decipher the scribbles on the whiteboard.
In a figurative sense:
* The author's early work was dismissed as mere scribbles.
* The politician's speech was just a scribble of empty promises.
The specific meaning of "scribble" will depend on the context of the sentence.