My most common use for Siri is creating lists in the Reminders app. My wife and I share a list titled "Groceries". This has replaced the pen and paper stuck to the front of the refrigerator.
I just realized that Siri will remember the most recently used Reminders list when adding items consecutively.1 So in one session, I start by declaring the name of the list but after that I can just add items without the list name.
Now I can just walk around the kitchen and add items to the shopping list like this:
"Add hot sauce to my Groceries list" "Add jalapeños" "Add sardines" "Add Pepto-Bismol"
Siri only has a very-short term memory. Once the screen goes to sleep, she forgets the list I was using. I think she had some sort of head trauma.
This may not be new, but it's new to me and I like it. ↩