Distinguish between someone else's dream and your interpretation of that dream.

It's a basic rule of dream etiquette to use "If it were my dream...".

The Golden Rule: When discussing other people's dreams,  always begin your remarks with "If it were my dream".

Consider the difference between "If it were my dream, the snake would mean my mother" and "The snake means your mother". That's huge. The first statement is Self-contained. It's about you and it's your opinion about you (and your view of yo' momma). The second statement contains an assertion that you know better about the dreamer than they know themselves.

Meanings are personal and whenever people look for meaning, the boundaries between people get murky: An apple means one thing to a kid and another thing to a green grocer.

This is always true. You never know what someone else's dream really means (and it's open to question whether "real" is an appropriate word to use in the realm of dream work)

There is a second reason for doing this: Someone else's dream can have considerable value for you but only if you own it and view it as your dream. 

Don't confuse your meaning for you with the dreamer's meaning for him/her.