Frankly, who has the time to remember little mnemonic devices like D.O.C.T.O.R. or P.L.A.C.E when right in the middle of a conversation? Even the little songs or raps didn't help me when in the middle of a conversation. [Excuse me, let me sing a little rap before I answer your question...NOT!]
With just TWO symbols, students can start to grasp the mindset of the Spanish speaker when describing things with TO BE.
As VanPatten has stated, our "mind" internalizes grammar subconsciously in its own time. We can merely provide "crutches" as if we are waiting for a broken leg to heal. These training wheels give students a quick reference to communicate quickly.If you are teaching towards proficiency and teach grammar in quick easy to grasp chunks or even want to go into more detail of the nuance of this grammar concept, you'll love this infographic.
Students say year after year that other than Por/Para and the Subjunctive, learning when to use SER and ESTAR is the most frustrating.