Jotting things down frequently from the beginning can help you move your ideas and results onto paper fast.
Good, coherent writing cannot transpire if you did not invest time structuring, testing, and refining your thoughts on paper. It is through continuously organizing, explaining and rewriting that you come to understand the deeper motivations and implications of your work. Treat the paper that you must eventually produce as a research plan in progress . Adjust your mind from the outset to enjoy the creative period of confusion and disorder that is the start of your research journey. Do not start planning and writing only when you have “all” the data. You will be overwhelmed. Start early and do it often!
How to plan?

Believe in the power of the pencil, paper and your hand. Writing and sketching things out on paper is the most straightforward way to plan your manuscript and research because there are no temptations to format anything and paper gives you the flexibility and creative freedom that computers just don’t. Besides, our brains are fired differently when writing than typing.
Sketch everything: equations, pictures, schemes, ideas etc. Use few words initially. Allow your ideas and thoughts to flow freely and jot them down as they come. Organize later. Writing makes something readable. You can revisit it, show it to others, collect, edit, organize and expand. When you don’t write things down, they might simply disappear.