Another method to remember it is to imagine that The Phloem is like the King in checkers it can move forwards or backwards unlike normal pieces which are restricted to moving only forwards. To cap:
Phloem can move Upwards and Downwards
Xylem can only move upwards.
if I confused anyone keep in mind that most plants stand up and a checker board is flat, meaning that they are on different planes thus require different wording. Hopefully this is also helpful for remembering the distinction between the two.