Students vary wildly in their ability to write essays, and to research them, and the variation goes far beyond the expected differences in innate talent – these differences are likely amplified by a combination of willingness to learn, work ethic, and fortunate choice of teachers. Essay writing and factual research, obviously expected from any academic by the Masters' level, are difficult to find good coaching for at the undergraduate level, and tend not to be taught when it would be most appropriate, in high school. But they are teachable, and indeed self-teachable in the willing, with a series of graduated exercises, careful marking and coaching, and some prerequisites that may be taught in the early teens. The best ways for a student to learn these skills at any age may be broken down into the individual skills, some great exercises, and a few helpful techniques. The basics skills of the trade include essay writing, critical thinking, and research.
Academic writing, to meet a minimal proficiency standard, must be well structured and clearly written. That means learning essay writing -- how to state and develop a thesis, to support it with evidence, and to link the evidence persuasively, right down to the conclusion. Skills like choice of words, signaling of intentions, and logical paragraphing can be taught and exercised. Essay writing classes are taught in high school and early undergraduate years of some courses, and as extracurricular courses in summer schools run by major universities.
Beyond simply finding papers, books and articles, it's important to assess their arguments for logical flow, lack of fallacy, and proper sourcing. Again, these skills are taught in online and extracurricular courses, and many countries are debating teaching them in schools. There are apparently political arguments against such teaching, as well as for it. But the basic structure of an argument and the recognition and avoidance of fallacy is a simple 12-week module that can be taught at nearly any level, and can easily be found as an online course or even a series of podcasts.
Research is best learned by doing research. Some of the skills are obvious – read the bibliographies of the paper you begin with, look at the papers it cites, how well-sourced are the arguments? Less obviously, Google Scholar will also answer the opposite question – what papers cite yours, how much credibility does it have, and where does it lead?
Research on the internet is an easily learned skill, but may require some training to do properly. Wikipedia is an excellent aggregator of sources, but not itself a source. A keen student will use it to find relevant papers, then use those papers to find more.
But not all these skills can be learned without trying them. Learning how and when to cite a source, when to follow up secondary sources, when to quote results directly, and when to apply one source's data to another source's logic, takes practice and persistence and good feedback.
If all else fails, some students may want to consider getting help from professional research services which would prepare a model essay. Sites like EssayCoupons.com feature one of the best academic research deals and discounts available.