I encourage the student to think of writing as a different form of talking. When we speak to one another, we do not do so like robots reciting a series of single numbers: "I went to the store. I picked up the milk. I went to the car. I drove the car home. I arrived here. I met you."
Instead, most of us naturally add fluidity to our conversations. In fact, we tend to speak in small to medium sized paragraphs quite instinctively and add artful transitions between our phrases. The worst writers can often speak in a fashion which, if put to paper, would make them appear to be above average wordsmiths. The problem lies in bridging that gap between the spoken word and the written one.
In order to facilitate that learning, I like to take the outline for a paper (if you have not put together an outline yet, then you are not ready for this step of the process!) and have the student talk to me about the topics as if we were having a conversation. I listen to what they are saying as well as how they naturally transition between the topics, and I restructure their spoken words into acceptable written form. Like follows:
Student
Well, every apple starts as a seed. When you want it to grow, you plant it in the ground but you have to be careful to plant it in fertile soil--apple trees don't grow easy. Then, the rain and soil will help it to germinate, get roots, and then sprout like a tiny plant. If you protect it--because most plants die before becoming trees so you have to make sure that doesn't happen--then after a long time you will get a small sapling. That sapling eventually grows into a full tree. That tree creates more apples and the whole process starts over.
Liam
Great. Let's look at how to translate that into writing.
"Well, every apple starts as a seed" can be simply "Every apple starts as a seed". Then, "Place the seed in fertile soil in order to begin the growing process." Then, "Given time and provided you protect it, the rain and soil will help the seed to germinate and sprout like a tiny plant. That tiny plant will become a sapling, which eventually becomes a full tree." Finally, you mention a "process" which is another word for cycle, so let's say, "The cycle is complete when a new apple grows from the new tree."
Now, often, I do this in much smaller chunks, but the process always remains the same. You get a spoken version of the soon-to-be written words and help the student realize that their ability to speak--and how they think about speaking--is their ability to write. Given enough practice, i.e. brick by brick, the gap between the two can be bridged and a student will find themselves confidently able to think like a writer.