
That Notebook
One of the things I always suggest you have is a notebook. It can be something beautiful that you love the look of, or it can be the most ordinary notebook ever. What matters is you write in it.
If you're working on a book, ideas will pop into your head often. You may have a chat with someone that gives you an idea. You may see something when you're walking in the countryside, shopping in the supermarket, on holiday, or sitting in a cafe.
These are the bricks to build your book with. And if you have already started writing your book, it's great to play around with the sequence of events, how you plan chapters, sources for quotes from other experts.
If you don't have a notebook now, buy one!