By stopping to search.

Remember the last infuriating quarter of an hour, spent frantically searching for your keys: your nerves are stretched to the limit, you search your pockets, your bag, you move the furniture, check every corner, even the most improbable, new searches your pockets, still nothing, the fever wins you, here you are now in the bathroom, on your knees, your head at ground level, you light up the dusty underside of the little chest of drawers under the sink thanks to the " flashlight" from your phone, your partner comes over, discovers you in that unflattering position and giggles "Hahaha!!! Baby, what are you doing? - I'M FUCKING FOR MY FUCK KEYS, THIS IS CAN'T YOU SEE?!", a violent argument breaks out, you bang your head on the sink as you get up suddenly, sharp pain, your anger redoubles, you storm out of the bathroom, hysterical, pissed, especially because your keys, against all expectations, were not there, your phone rings, you pick up violently, by reflex, it is your neighbor Mrs. Kasscouye who calls to ask you for the number of your mechanic, politeness obliges you to contain yourself, you calm down a little and ask her to wait a brief moment, the business card garage is at the entrance, in the storage compartment on the shoe cabinet, you go there, a painful bump has already formed on the right side of your forehead, at the other end of the line, Madam Kasscouye now sets out to imitate the strange noises emitted by the engine of his vehicle, you laugh inside, once in front of the storage compartment, a furtive metallic shine behind the container attracts your attention, you lift it nonchalantly and discover, amazed, your key ring.

What you consider lost or hidden cannot be revealed to you.

If you are looking for something, it means it is concealed, so it will remain so.

Let go of the tension created by your futile efforts, let go, change the subject, do something else in order to settle into a receptive state and you will see, in the middle of a moment, sometimes even the most incongruous moment, when you do not think about it, even more, a host of ideas for writing will simply reveal themselves to you.

By the way, these ideas are still available to us, sitting there in the ether, but sometimes we are too restless to search to see them.

The real question is why do you want to write. In the digital age, globalization, and everything that surrounds it, writing a book is far from being a way to earn a living. Not even to be popular or to have a fan base.

One plausible answer is, I want to write because I have a few things to say.

But lo and behold, your question suggests that you are “empty”.

Don't worry, we all are a bit.

Writing is a mechanical habit that you can pick up and do every day.

Know that it is not given to everyone to be a good writer, a good writer writes for oneself but also for others. And he usually has a message, a lesson to share.

The idea is that to love reading, you have to dedicate a lot of time to it. Research time to find good titles, time to read the book, and money since the books are not given away.

As such, as a writer, you have to be able to provide quality, a matter of respect for people who spend time reading what you have to say.

Recently, I have an acquaintance who finished writing his book, it took him more than 2 years, and he barely sold 200…

As explained above, above all, you need a real desire to write. This makes the process even easier.
You also have to be sensitive to your external and internal environment (although there is always a connection between the two). Think of something that touches you, be it a place, a person, a memory, an emotion, a reading, a current or historical event, etc. We note, we cross out, we erase until we open a path. But the hardest part, in my opinion, is not finding ideas, but turning them into concepts.

For every writer, this is the billion-dollar question none of us seem to know the answer to. How do you find ideas to be right? Most of the times, when I ask myself like this, I'm either in the middle of a huge financial or existential crisis and if neither, the question makes sure it takes me all the way down to one. A glimpse of this would be to say, I begin to question my writing capabilities altogether, can I even write? do I have ideas worth jotting down? What if I am just fooling myself?  

Then, I try to shut my mind down and head outside, where my ideas actually reside. I have noticed that my brain runs the wildest when I am walking. It comes up with questions I never knew I wanted answers to and shows me sides of the stories that didn't exist for me a moment before.  It brings about such a change and I head back inside my room less of a man and more of a philosopher. So, to me, that is how I 'find' ideas, I look for ways to leap within my own existence and swim around. For as long as I am continuing to look for myself within myself, I shall continue to be a writer. 

For me, writing comes pretty easily, out of mundane things but for that, you have to learn to hold onto things. The last time I got into an argument about gender equality, I made a mental note of everything that was pissing me off and what counter arguments I had for it (even if I didn't say it outloud). So, as soon as I had access to my phone, I wrote it all down and then published an article under the tag of gender equality on my blog. 
Quite similar is the case with creative writing, I look at the sky and I can think of things to write about. Heck, a broken mirror on a bathroom wall can give me so many metaphors and what not. So, if you wish to be a good writer, be vigilant about things around you and mindful about things that need to be voiced.