Some journal editorials are ONLY introductions to the current issue from the editors, which is not what I cal a true "editorial."

When I think "editorial" I think of a discussion of an important issue or policy.  I think that you write such an editorial as you would a formal speech:

1. State your introduction and your "thesis" about the problem.

2. Explain any needed background

3. Give each of your main points, in turn, with supporting evidence.

4. Present your conclusion that re-states or expands on your thesis.  Depending on the issue, you may also include a call to action with what you want readers to do.

Read five such good editorials, and you would be able to write your own.

 Thanks Bin Jiang. I did. Some are long, some short. Some are full of publicity or praises for the journal. Some use lot of acknowledgements some don't. I was just looking for an evaluation rubric?

Some journal editorials are ONLY introductions to the current issue from the editors, which is not what I cal a true "editorial."

When I think "editorial" I think of a discussion of an important issue or policy.  I think that you write such an editorial as you would a formal speech:

1. State your introduction and your "thesis" about the problem.

2. Explain any needed background

3. Give each of your main points, in turn, with supporting evidence.

4. Present your conclusion that re-states or expands on your thesis.  Depending on the issue, you may also include a call to action with what you want readers to do.

Thanks Michael W Marek. Valid points.

I quite agree with everyone's comments

from others editorials you gradually develop your too

Start from the questions: what, why, for whom. Be not two long ( ideal 1 & 1/2 page). Use positive active sentences. Find a good (means: critical & sincere) copy-editor.

I agree with earlier writers that this comes with experience but one can start looking the various editorials at middle level journals and then slowly move up towards top quality editorials. A good editorial provides opinion(s) of editor on a topic. It also gives an overview of works covered, upcoming trends and futuristic technologies etc. In nutshell Editor provides his critical observations on the works covered, gives only essence of the works covered in the issue. Some times editorial will be a bit long gives the summary of research in that area along with references.  All the best for your new venture and bold steps towards inexperienced area!!!

Good editorials address a current need.  For example, a journal may be receiving a high percentage of manuscripts that do not appear to be well-suited for the journal.  In response, an editorial board member might write a piece detailing the qualifications of manuscripts that are a good fit for the journal, and how to write a manuscript to effectively communicate these qualifications.  Another example, could be if a journal is not receiving manuscripts in a certain category (e.g., case studies).  A member of the editorial board, in such a situation, could write an editorial detailing the importance of case study manuscripts and providing guidance regarding how to write a case study for publication in that particular journal. I hope those examples are helpful!

 Thank you all for your valuable feedback. The question was about writing a research journal editorial. I was looking for some valid resources for that apart from expert opinions as I could not find much. Of course it is an inductive approach to read available editorials and derive rules of the game. Also editorials' take different shape based on the discipline they cater. 

Thanks again.

In the pre-open access publishing model , editorials were authored upon specific requests from the section editors of a specific journal. The section editors usually defined the guidelines for the editorial, which was authored by a figure considered an expert in his / her field.

In  our days editorials, specially in open-access journals, can be authored without any invitation , just following three simple rules : (1) A thorough coverage of the pre- existing literature ; (2) Critical review of all presented ideas;  (3) Proposals for future studies.

@ Ayesha Perveen, may I share one editorial I have recently done?

Article Editorial: Spatial Heterogeneity, Scale, Data Character, and...

I must say that this editorial is a naturally occurring, while I was working on something else; see the acknowledgement. I believe every piece of writing must have some key messages to convey.

Thank you Bin Jiang. Agreed, it should be informative.

Depending on the journal, a good editorial (opinion piece) should have a short but comprehensive introduction, background with supporting evidences and informative conclusion.

Thank you Nyakno Jimmy George. I see some editorials presenting references at the end while other as a simple piece of opinion, some with facts and figures about the journal and others very specif to the edition theme. Actually there is a good deal of variety based on the domain and style of the journal. I wonder if we can develop a rubric for a good editorial.

An editorial about what findings or research would be a bit dry and cold, but an editorial about implications of some research would be living and profound. Or an editorial about the state of the art would be a bit dry and cold, but an editorial about research vision would be living and profound. Herewith some tips about scientific writing in general: Presentation Scientific Writing and Publishing for GIScience Researchers

Agree with Michael W. Marek

regards

Editorial is a writing genre whereby a particular writer, usually the editor, expresses a newspaper's or publishing house's views and policies on an issue of specific interest. Characteristically, a good editorial should have:

1) A clever use of reasoning strategies brightly representing alternative views expounding the targeted issue,

2) Evaluate moral values based on facts,

3) Represent a sense of prose as being very perceptive, thoughtful, and responsible,

4) Motivate readers and grab their interests,

5) A focused central theme.

Would not repeat what has already been stated.My input is that a research journal editorial may highlight the key questions valid for the journal from its location standpoint. For instance an editor working in Algeria or Brazil or Pakistan will have varying priorities. Whereas there can be universal themes, applicable to all, there are always themes particular to a region. This adds the local flavour and may make the difference between average and good editorial. Regards.

@ Ayesha Perveen By the five editorials, I meant those you like most, those you wanted to set as a mirror for your own writing, NOT all kinds of editorials. One must learn from other writings, which is the most efficient and effective way, although there are some writing principles or tips:Presentation Scientific Writing and Publishing for GIScience Researchers

I agree that editorials should be short, succinct, to the point, and address the topics relevant to the audience of the journal. It should address, but not necessary, the current common theme but with a new view/angle and contain relevant information. It might contains references, if possible.

Like any effective writing and speech, it should also follow the structure that Michael W. Marek spelled out above.

It should be less than a 1,000 word.

Some journals as this one attached use the word Preface to refer to Editorial.

I am learning here.

May I share with you of this recent editorial?

https://www.mdpi.com/2413-8851/3/1/30/htm

I think that a good editorial should be interested in its originality and the presence of ideas.

I understand that Editorials are normally invited submissions usually involving someone from the Editorial board. They are written by experts in the specific theme of the editorial usually about a recent topic of interest. A reader would expect the same to be crisp in nature, with a good logic flow, which will update or introduce to an interesting topic in a short time.