One place I find that is in the shower. As I take a leisurely shower, thoughts flow into my mind regarding whatever I'm working on at the moment. I get all sorts of ideas that I can either reject or follow up on later.
Another place I find it is in the car. I pay attention while I drive, but if I leave the radio off, a part of my mind wanders free and sorts things out.
Walking can be a good time to do this as well. Since I usually walk with a partner, we think out loud as we go. We've sorted out all sorts of issues and generated lots of ideas as we bounce thoughts off of each other. Many of them are rejected but it's fun to see what pops out of our psyches.
Sometimes thoughts directly related to the day come in during that morning "just woke up, not ready to get up" period. I don't usually have to wake to an alarm, so that's a good time for me.
I guess the whole point is to slow down. Our frequent hurry-up pace can crowd out the chance to pause, to reflect, and to leave our minds open. Got some waiting time? Find that peaceful mind place and let it go to town. You might solve a big problem or mentally plan a meeting while waiting for the carpool. You might change the course of your whole life while standing in the shower. You might peacefully find that you are on exactly the right track at the moment.
We often consider open-mindedness as being open to new information and other people's ideas. I invite you to open your mind to what's inside it and see if great ideas come out that will help you grow and learn from what you already know or have done.
One caution: if you do this when you are angry or resentful, the ideas that come out may not be the most sane. Examine them carefully! Fear can do it too. Even in peaceful times, not everything that comes into mind is helpful. We have the freedom to keep what to choose and what to dismiss. Also, headache or pain can block the mind opening if we are focused on it. Maybe that's why the shower is good--it provides temporary relief from those.