Writing comes easier after you start writing. It may seem counterintuitive at first but it makes sense because that’s how other activities work, too. For example: running is difficult after you’ve just woken up. You need to warm up your body, get the blood flowing and the muscles working. Once you start running for a few minutes, your body is in a much better shape to continue with this activity. It’s the starting that’s hard. With writing it’s the same, but instead we keep looking at a blank page waiting for divine inspiration. It won’t come. You have to start writing to write.
Two things happen when you do. One: you will probably write something stupid. In this case your brain will pick up on this and will immediately begin to construct an argument against what you just wrote. You’ve sparked a thought. Two: as you try to form sentences, your mind begins to form longer thoughts, making ever more connections between concepts in order to better formulate your idea. This process is essential for writing, but writing itself is also the thing that helps to start and strengthen it.