Aways have writing tools on you.
Phone. Pen and paper. Laptop. A recording device. Whatever works for you.
There will be moments when you'll have a great thought, a wonderful idea. Jot it down. Stop doing what you're doing and catch your inspiration by the tail and quickly write it all down.
This is what we used to do as kids. Just do things spontaneously.
Then we grew up into adults who have forgotten how to be present, in the moment. How to spontaneous. "I'll do it later when I have time." That's our excuse.
But there is no later. There is only now.
And you're do it much faster if you write it in the moment it strikes you, even if it means breaking an important dinner, apologizing, and disappearing into the restroom where you can be alone for a good chunk of time.
In the accumulative math of the hours of your life, you'll save time by breaking your routine.
Learn how to listen to yourself, and be a kid again. The writer in you will thank you.