All Latter-day Saints are called to be apologists in some limited way, that is, to defend the Gospel if/when the occasion calls for it (see 1 Pet 3:15-16 and D&C 71). Of course, there is no "calling" or "office" of LDS apologist, and some are not equipped to "do" apologetics on a regular basis as some of us do, and that is fine. However, for those who wish to enter the realm of LDS apologetics, here are some “tips,” in no particular order and in no attempt to be exhaustive, for those who wish to become an effective Latter-day Saint apologist:
(1) Have a spiritual witness of the truth of the Restored Gospel: No one should enter the realm of apologetics unless they know the truthfulness of the Restored Gospel. I have seen many enter apologetics just to “get” the testimony they desire—it doesn’t work that way, and unless one is built on the rock of revelation, one’s foundation is that of sand.
(2) Know the Scriptures intimately: This is also central. One must know the Scriptures (and yes, that includes the Old Testament!) very well, but one must make sure that they read the Scriptures daily, and have some plan to get through all the Scriptures at least once a year.
As for myself, I usually read 5 pages of the Bible, 5 pages of the Book of Mormon, and a section or two of the Doctrine and Covenants/Pearl of Great Price each day. I usually go through the Bible cover-to-cover in 255 days; the Book of Mormon in 80 days; and the Doctrine and Covenants and Pearl of Great Price usually gets read, cover-to-cover, three times or so a year.
A good plan would be to try to read each of the “standard works” cover-to-cover each year, not one after another, but with one another.
If one wants to get "hardcore," learning Koine Greek and biblical Hebrew and investing in a Bible software programme would be a good idea (I studied biblical languages in university and I use Bibleworks [I also sometimes use Logos]).
(3) Read LDS Scholarship and Apologetics: Rather obvious, but has to be said. Make sure one reads the best the LDS side have to offer, and ensure one does not needlessly “reinvent the wheel.” Many arguments have been answered so thoroughly that simply linking to a general article on the topic will suffice (e.g., the “Adieu” argument from Jacob 7:27 or Rev 22:18-19 as a “proof-text” against post-biblical revelation, etc). Being familiar with the previous work of the Neal A. Maxwell Institute during the time of Daniel Peterson, as well as that of Book of Mormon Central, FairMormon, the Interpreter Foundation, the works of Blake Ostler, and others are essential.
(4) Read non-LDS Scholarship: One will get a lot of insights and (positive) intellectual challenges when reading non-LDS scholarship on various issues. Indeed, much of my work on the New Covenant Priesthood was a result of reading Roman Catholic scholarship on this issue, as well as works on the theology of the Eucharist, just to give one example of many.
(5) Read the best the “other side” has to offer: Yes, one will have to read anti-Mormon “literature,” but one should also be well-read in the best works from the other perspective. For example, many of our critics are Calvinists, so one should read the works, both historical such as those of Calvin, Turretin, Charles Hodge, as well as their modern apologists such as R.C. Sproul, as well as confessions of faith (e.g., the 1646 Westminster Confession of Faith). It is essential that one not only knows what one’s theological opponent believes, but why (the theological; biblical; historical reasoning behind such doctrines).
(6) Know how to spot historical and logical fallacies: This will allow you to (1) ensure you don’t engage in them and (2) you can point them out in your opponents’ argumentations. Some good works on this would include David Hackett Fischer, Historians' Fallacies: Toward a Logic of Historical Thought; Peter Kreeft, Socratic Logic; Bo Bennett, Logically Fallacious; D.Q. McInerny, Being Logical: A Guide to Good Thinking.
(7) Engage in apologetics for the right reasons: We are all called to defend the faith as well as provide the strong reasons for belief therein, and that is what apologetics ultimately is. It is not to “show off” one's knowledge; it is not to “embarrass” others, etc. I will readily admit that, when I was younger, I did have a more acidic attitude and would engage with people just to “show them up.” Fortunately, I have repented of such an attitude, albeit, imperfectly. If one is wishing to enter the realm of LDS apologetics just to vent, show off, or simply to embarrass people, such is not proper as it goes against 1 Pet 3:16, where one is called to glorify Christ in their apologetic. At the same time, one has to be forceful at times, as truth and eternity itself is at stake.
(8) Read, Read, Read!: The most effective apologists are bibliophiles. One must enjoy reading and studying. That doesn’t mean that one must have a personal reading library of 7,000 volumes (as some of us do . . .), but one must read on a daily basis, even if it is “just” a few pages of a book or a journal article, etc. If one does not have as much time as they wish to, they may have to make some personal sacrifices (e.g., give up 2/3 hours of television a week) to dedicate time to reading both the Scriptures as well as other works.