Written notes are nothing new, but they are best when they are concise and clear as to your ideas and objectives, they lay bare everything in word format for your ideas to be described and planned in a way you know yourself that it will turn out right.
Writing ideas down on paper is something that every artist should do to accompany their sketch notes to give a clear emphasis of their work and record it for future reference. A good folder can be used for the storage of these notes, and it is best to label each plastic sleeve within for ease of finding the right ideas for a given project.
You'll find that every time you write down your notes and ideas about certain things that you'll always have a full library archive of ideas to use as you go along with your art.
Breaking down your ideas archive down into categories, you want all of your clear ideas at the forefront and all of your vague ones at the back of the file as this helps to make your folder more organized and more inspiring to read through.
I like to add one full A4 size sheet of written ideas and then place a sketch filled A4 size piece of paper on the back so that I will be reminded by a visual reference for my ideas. This would be something that I could flick through and just see the sketches or the written notes depending on how much time I wish to spend being inspired and engaged with some current ideas.
When the boredom of doing other tasks sets in, I suggest writing a few random ideas down on a small pocket size notepad and you keep one of these in every room and every drawer so that when the moment hits you, you can jot down ideas before they slip away.
I buy my pocket sized notepads from Asda which is a uk supermarket owned by Wal Mart and they are around 10p each, which is just great as I now have loads all about the house.
If writing the traditional way isn't for you then create notepad files on your computer and save the notes on your hard drive, just remember to back these up on disk (because losing your ideas electronically is just not fun!!)
I cannot stress how important it is to organize your written notes and you could go as far as keeping them in alphabetical order if this suits your way of thinking and makes it easier to find specific ideas.
The very fact that you write your thoughts and ideas down, means that you are cataloguing and making sense of these ideas and creating value for them at some point, much like a blog, the whole point of thinking of new ideas is so that they will be used later on and provide value to someone other than yourself.