tiptoe vs watch one’s step

tiptoe

noun
  • The tip of the toe. 

verb
  • To walk quietly with only the tips of the toes touching the ground. 

adj
  • Standing elevated, on or as if on the tips of one's toes. 

  • Moving carefully, quietly, warily or stealthily, on or as if on the tips of one's toes. 

watch one’s step

How often have the words tiptoe and watch one’s step occurred in a corpus of books? (source: Google Ngram Viewer )