The hardest step in writing Research is in writing down the first words. Begin immediately. Write your research proposal carefully, with a few keyreferences. Update it periodically. As you take a step, document it! The second hardest step is in polishing the work at the end.
My opinion, the hard step in the good writing of the researcher which is at the heart of the subject and avoid the researcher astrology as well as the exact and logical interpretation of the obtained results.
In many ways the planning is hardest. A poor plan will usually result in a poor paper.
First identify the TOPIC you want to address. Then seek gaps or unanswered questions in the current literature. Evaluate which you can address within your resources. This will lead to research questions, methodology, etc.
There are two difficult tasks at two stages of writing:
1) Before you are starting or when you are starting: to actually begin writing. You have done the structuring, you worked on your layout, but maybe you believe you could do some more work on it. Prepare more thoroughly or collect more files and data than you already have. There are thousands of reasons not to start, which makes actually starting so difficult.
2) When you are actually writing or should be about finishing: Cut down on text. Now you are in a flow, words jump right from your pen onto the paper or are thrown at the screen via your keyboard. They are flooding out, there is no stipping it, but remember: there are key aspects to deal with and your paper/book/report has a focus. No matter how intreaguing some sub-topics might be, how funny little historical tales of secondary characters, they might not belong and blowing a text out of proportion happens easily.
2b or 3) This one belongs to no 2) even though it should be at stage 3): finishing! How many people have you known who find it hard to bring a book to its end? So much to write! When its done and sent in there is no stopping it, you might have improved the text if only you had the time. Well, you gotta stop at one point and a book done is better than the best unpublished book in your drawer that nobody reads.
Choosing a topic may be from your own field of specialisation/ expertise. The first step which I feel hardest is FIRST WRITEUP/ PEN DOWNING your idea/ thoughts i.e. to give words to your thought....The second hardest is to make it more concrete with help of field/ laboratory data, depending upon subject concerned...The third hardest naturally the explanations towards the available thought and data.....The fourth .the final one is to make your text/ interpretation part more readable (obviously for the audience/ community going to read it/ people from your own field of specialisation) and to make someone understand what You actually want to convey, based on your work/ research work/ findings etc.