According to the Bais Yaakov of Izbitz on Parshas Vayikra, Kedusha is "hahefech midevarim shel mabakach."
If I want my life to have kedusha, I can't treat even the most "mundane" part of it as a "davar shel mabakach." "Mabakach" means something inconsequential, trivial, or meaningless. I tend to think that certain things I'm doing like eating, working, chopping tomatoes and cucumbers are inconsequential and therefore I don't put any thought or effort, spiritually speaking, into how or why I do them.
But kedusha means treating everything I do like a big deal. Rav Kook says that small people do even big things with "smallness." But big people (Gedolim) do even small things with bigness (gadlus).
So make every moment big!