相
=
木
+
目
:
Mnemonic symbol: I take "eye" and "tree" as resembling an ent, an alive tree. Xi Shi (xi) portrays (相) an ent (相) in the anglepod's bathroom (ang4). Unfortunately she's really bad at painting, and her portrait resembles more a Christmas tree (木). The Eye of Providence (目) enters and, just from the shape of the Christmas Tree, instantly recognizes its own portrait (相).
争
=
⺈
+
肀
:
Mnemonic symbol: The grim reaper, as 争 is often used in words involving war (...战争). In front of the engine ((e)ng1), the grim reaper (争) marks his next victims in passing. With a crayon (肀) he draws big "X"s on the crane (⺈) and James II of England (zh).
lit. when the snipe and the clam grapple with each other, the fisherman catches them both (idiom) / fig. when two sides are locked in dispute, it's often a third party that benefits