Like most people here, I use the default Wands - Cups - Swords - Disks order, because it nicely follows the compass rose and because active and passive suits are balanced that way as well as the elements. I think of the four worlds of the kabbalah, too. Atziluth is the Wands realm, Briah Cups, Yetzirah Swords and Assiah Pentacles.
I order my decks often, it's my way of "neutralizing energy", i.e., wiping away the traces of the last reading. Spending some quality time with my decks often means ordering and shuffling them. It keeps them warm and fresh.
Sometimes, I use other ways to order them, according to numeric, kabbalistic or astrological associations, depending on what I'm studying right now.
But usually, I order them from the Fool down to the King of Disks.