Honestly the dedicated shutter button on my Sony Xperia. I have ADHD and I want to remember something I press the button and take an immediate picture. At work I use this function constantly. I’m a repair technician and it’s really nice to take a picture of a model number instead of having to cross reference between the computer screen and the computer I’m trying to fix.
Listening to music is also good.
I can’t believe I forgot this but GOOGLE. Anytime, anywhere you just have to know something, or learn how to do something you can immediately search it up.