Ser and estar - extended
Some time ago I wrote a post on the core differences between ser and estar, so check that out to see some more examples.
However, there are some expressions and specific cases that might be trickier to understand with just the base rules.
For that, the table below can be a quick cheat sheet that provides a more complete picture.
As you can see, it includes the basic difference:
SER: Not likely to change quality feelings
ESTAR: Mood, feelings and states likely to change
Hope it helps!
¡Hasta pronto! :)