The default Notes app on the iPhone and iPad is a great place to scribble down random thoughts. If you use it frequently you've most likely come across a time where you wish you could jot down a thought before you lose it. Luckily, if you're in a hurry you can ask Siri to do it for you!
How to dictate a note to Siri on iPhone and iPad
Press and hold the Home button on your iPhone or iPad to launch Siri.
Say "Take a note."
Dictate your note to Siri.
Once you're done talking Siri will automatically save what you dictated to the built-in Notes app.
Press the Home button to return to your Lock screen or Home screen again.
Dictating notes to Siri may not be perfect in its current form but it's much quicker than typing them out. Then when you have time later, you can go in and add a title and change anything that needs to be added. Give it a try and then let me know how it works for you in the comments!