At this point we all have agreed that non-academic PhD jobs are a must, for various reasons that have been widely explored on previous posts. We got now to the point where our CVs have been shaped and tailored and we are ready to cover them with some nice arguments in our favour. That is the primary function of a covering letter. I tried to find compiled information that could drive you straight to the point; no gibberish, no small talk. And thus I found June Kay, Kailey Barney and Dorie Clark.
As Kailey Barney suggests, a cover letter is a brief document where you offer an introduction to you as a candidate, summarise your suitability for the role and explain how you can be contacted .
June Kay is a Careers consultant specialising in helping researchers and graduates. Just like June Kay says and to be fair I've seen it sometimes from colleagues of mine, cover letters are underestimated. That is wrong and somehow stupid. Imagine you were trying to get the perfect professional for a job; you read her CV and it goes side to side with someone as good as her. How will you scrutinise the most adequate one for the role? By the content of their cover letters.
So as June so well states, the content of your CV should be factual and highlight your skills, knowledge and personal qualities that are immediately important for the role you are applying for. However, the reasons that made you apply for that very specific job are not embedded in your CV or resume, they follow in a covering letter as a complement that supplements.
Your covering letter need to reflect on:
- your Personality;
- the Values of the organisation matching yours;
- the exact Nature of the role you've applied for (a generalist one is a shot on your own foot).
The obligatory content of your covering letter:
- Where did you see the vacancy advertised?
- What caught your attention?
- What aspects of the job description excite you?
- What especially relevant experience or skills do you have?
- How do the values and ethos of the organisation and job sector match your own?
- Where does this role fit in your overall career plan?
- When are you available for interview/to start this role?
- Make it succinct, polite and professional! [1, 2]
- Stop using general ideas that they can read anywhere else; show them why you are special.
- Drive, passion and enthusiasm are crucial - if you don't have that when considering such and such role, let others have it because you won't fit. It is a matter of social/professional responsibility.
The size of your covering letter:
- one A4 page in length, one and a half if you are that incredible and yet succinct.
What not to include:
- Do not include your current wage;
- Do not include you expected wage;
- Forget about telling them why you are looking for a new job (that will probably surface at interview level);
- Do not repeat the content of your CV. 
A final remark on self-confidence:
Coming across the wrong academics and the wrong academic experiences in your life can really devastate your self-confidence, if unfortunately that is the case. The biggest mistake I've seen these people do, from supervisors to technicians, colleagues and the like, is to portray a failed attempt as if you were a failure. I've seen people abandoning their PhDs right at the start or half way through because they came across some egocentric idiots who made them feel like losers rather than helping them pick up from the empirical lessons.
Dorie Clark heard about over-criticism when discussing some viewpoints with her readers. Some of them experienced the "one strike and you're out" attitude toward failure. Even if this was in a somewhat different topic, the typical killer attitude is yet another proof of a rotten society we've been building based on exaggerated optimisation of processes that ultimately determines an exaggerated emotional coldness and competitivity.
Failure is in fact an ongoing real process and the best trigger to learning. It is not a rarity, it does not make you a failed individual. Innovation requires failure, Success is based on the strength gained after failing massively . If you pick up yourself after a really hard blow you are proving yourself that your resistance is strong, all you have to learn now is to analyse where it went wrong and make sure you gradually apply the correct model. Use that confidence when communicating your qualities! Think about it - If there were perfect people they wouldn't be people, would they?
 What not to include in a cover letter for a job, allinnetworking, [http://allinnetworking.com/archives/4360], last visited on the 27th of March 2015, last update unknown.
 Covering letters for non-academic jobs - Tips for researchers, LinkedIn Pulse, [https://www.linkedin.com/pulse/covering-letters-non-academic-jobs-tips-researchers-june-kay], last visited on the 27th of March 2015, last updated on the 13th of March 2015.
 Stop believing that you have t be perfect, Managing yourself, [https://hbr.org/2014/10/stop-believing-that-you-have-to-be-perfect/], last visited on the 27th of March 2015, last updated on the 8th of October 2014.