Q: How can I start writing my journal article?

If you read the description of the question How should my literature review be structured? you will see that the person who posted this question is a BSc. student and the literature review is a part of his/her class project. Your case is different. If you wish to publish articles in journals, apart from identifying the topic, you also need to decide what type of article you wish to publish. Since you are a PhD student, I assume you will be conducting some research and your articles will most likely be original research articles or empirical studies that involve conducting experiments and collecting original data.

If you plan to write original articles, the literature review will only be a part of the articles. You should definitely start by reading relevant literature as this will help you identify gaps in the existing literature and help you come up with a research question and objectives for your study. Once you have these in place, you can come up with study design and conduct your experiments.  

Start writing your manuscript with the Methods section as this is the easiest and most straightforward. Follow this with the Results section. You can then write the Introduction and Discussion sections as you will have formed a clearer idea about your research by then. The literature review that you write will be a part of the introduction and will be structured differently from the one described in the answer to the question How should my literature review be structured? 

Here is a brilliant resource that will guide you on how to write a research paper: The complete guide to writing a brilliant research paper

With over 50 articles and 7 video tutorials, it is a curated list that covers all aspects of writing a research paper, including ethical considerations, style and formatting guidelines, structure of the paper, and more.

 Related reading: 

• A young researcher's guide to writing an original research article
• How to write the literature review of your research paper