When I speak about a person who can prescribe a practice to someone else, I refer to one who guides and really knows what he or she is doing, and can apply the practice appropriately - which means in the correct way, time, and manner. That is not the case in many situations. Many times a practice is offered because someone did it previously or it was considered to be good. Sometimes in a "non-teaching grouping" (which I differentiate from a group) it is thought that the practice is appropriate for everyone. Sometimes it is offered or given even though the one offering it has never done it; and although perhaps he or she did try it he or she gave it because that "non-guide" found it useful and then figured it would be good for anyone. That is almost never the case. In addition, most folks I have observed or come across generally want "something to do" - especially if it can be flashy and "spiritual".
Usually what a person is drawn to is NOT what he or she actually needs. Because someone is drawn to something, or wants it, is not an indication that it is appropriate at the time. A real guide must be aware of the condition of the person he or she is working with, and be aware of what that person needs at that time. Then, and only then, can an appropriate practice be prescribed. Obviously, this applies in conveying most skills; assisting a person in becoming proficient in a craft or sport or profession. Unfortunately, it is often not applied in the so-called spiritual realm. It is just common sense that it would be; but seems to be overlooked or not considered. Be aware also that there are many situations in which the "best practice" can be not doing anything of a spiritual nature. Sometimes the best thing for a person can seem quite mundane or be something to do in daily life. There can be many reasons for this. It is then up to the guided one to try and follow this guidance - having the faith and trust that it is correct for him or her - instead of what is desired.
Having said what I have about using a practice, if you decide to try any, understand that you accept and take full responsibility for doing so. All I can say is just to be careful. You do have a heart, feelings, and intuition. Try to follow them. Before trying something, I suggest you attempt to put aside any attraction it, quiet your thinking, follow your breath, and ask yourself - and then really consider - if it is appropriate for you now or not. Then, try to follow that feeling. While the writing on Teaching and Learning does include much information on discernment, there will be other writings that will go into more detail suggesting additional ways you can use be aware of what may be correct and/or appropriate for you at any given time. Whether you apply that guidance correctly, incorrectly, or at all, is up to you.
In the mid-1960s there was an odd little fellow by the name of Sam who periodically would have small meetings held in an apartment on Clementina Street in downtown San Francisco. He had all sorts of spiritual titles and was recognized by all sorts of groups with various names which reflected various levels. Much more valuably he knew the Real and knew what he was doing. At one of these I attended, during the course of the evening he gave a practice to the group there. I have adapted it slightly to this setting and added a few preliminary steps, ending with simply breathing love. Take your time.
Sit quietly with your back straight and hands in lap.