References:
[1]. Joe Fitzsimon's response to this thread.
[2]. Piotr Migdal's response to this thread.
[3]. arivero's response to this thread.
Brief
Writing papers is no different to writing anything else, although with scientific papers, that has less to do with vocabulary than writing a novel, so you are not in such a bad position. However, that still leaves style, content and substance to be addressed, let alone how to keep your reader/reviewer reading.
The key, as with all writing, is to keep your reader interested. The only difference with scientific papers is the context in which it is read, and the reasons.
Reformulating other Responses to this Question:
To reformulate other responses to this question [see the references], the phrase "keeping readers interested" means:
a. Relevance: Writing a paper that is relevant to other researcher's work. As JFitz says, make sure your topic is current and not on a subject that has been closed.
[Ref: 1]
b. Standards: Figuring out what is the standard for scientific papers in your field. Hence JFitz's suggestion to read a lot of papers in your field. If your paper doesn't match current standards, it will look unprofessional.
[Ref: 1]
c. Think Like a reader: communication is all about being able to put yourself in the shoes of your reader. You presumably know more about what you are writing than he does, so your reader is at a disadvantage. You need to make the structure of your paper march in step with the development of the ideas.
[Ref: 2]
d. Language: The language of physics is mathematics, so you can rely on this to convey your results. However, the odd good analogy helps. Just be careful of metaphors, they are pointless and irritating unless you are addressing laymen.
e. Peer reviews: For learning to write novels, there are peer review sites, such as Authonomy.com. I have never seen one for polishing papers, but there's an idea.
[Ref: 1]
f. References and summaries: put people in the picture. If you can't summarise what you are trying to achieve in a couple of short paragraphs there is something wrong. The references give your reviewer/reader a handle and places to look for background information if they don't get what you are on about. No paper is an island.
[Ref: 3]
g. Brevity: Long paragraphs are boring unless you are Charles Dickens. But then you wouldn't be writing papers...
Conclusions:
The responses here say as much as they can to you. Most people would work as part of the scientific community, and therefore, they don't need to ask these questions: the institution they work for hammers it into them.
But even if, nay, especially if you are working for some such institution, I hail you for making the effort to improve your papers.
If, on the other hand, you are working in the patents office in Bern, we will all be grateful for any extra clarity in your writing, and I hope that we have helped.
Help yourself by helping others is what this site is all about.
Parting Shot:
The reason for writing this response (apart from the two original contributions) is to illustrate that structuring what you write adds clarity and makes it easy to look up external references, as well as to help the paper be used itself as a reference.