Ratika Deshpande: ‘Write it right now.’
And don’t worry about hoarding ideas. Don’t save the precious idea that you think you will tackle later in a separate piece–you’ll never do it. Write it right now. You won’t one day suddenly stop having thoughts and ideas and opinions. New ones (to you) will keep cropping up. And they will be built upon the ideas you think about right now by writing about them.