First a little clarification. Some Wicca 101 books talk about Drawing Down The Moon (DDTM) as a ritual where a solitary Witch draws energy from a full moon to charge an item. This is a worthwhile ritual...but it is NOT what DDTM actually started out being understood as, nor is it what is practiced in Traditional Wiccan covens.
Drawing Down The Moon is a ritual act where a Goddess is drawn into the High Priestess, using her body as a vehicle where the Goddess can speak directly to the members of the group. (Alternatively Drawing Down the Sun is done in the High Priest.) It is an act of ritual possession where the personality of the High Priestess steps back and permits the Goddess to take over here body. Most High Priestesses that I know who have done this have little or no awareness of what is said or done during the period when the Goddess possesses them.
Since one always has to be careful during possession work that the entity invited is the entity that appears such work should only be done within a strong and properly cast circle. And since a temporary gate must be opened in the circle for the Goddess to step through, it also requires that one have trained coven members to monitor that gate and make certain that nothing other than the invited Goddess comes through.
In order to insure that one manifests the Deity that is desired it is a very good idea for the High Priestess to be very clear in her invocation as to which Goddess is invited. Leaving that open to chance is a good way to encounter aspects of the Goddess that aren't what you are expecting. For instance you might be expecting Aphrodite and end up with Eris. This isn't a catastrophe, but it can be unsettling.
I do not recommend that anyone try to do this on their own or without appropriate training. For one thing, since it is unlikely you will recall anything the Goddess might say it isn't particularly useful for a solitary. For another, one needs the additional help of covenmates to insure a successful and safe Draw Down.
Drawing Down the Moon can be accomplished in a number of ways. I have done it using two of them and both worked equally well. Most important of all is that the Priestess be trained and confident in her work and that she is comfortable with relinquishing control of her body to the Goddess for the period of the Draw Down.
There are some side effects that often go with Drawing Down the Moon even in a properly trained Priestess working in a trained circle. Some disorientation immediately after the DDTM is not uncommon, even some physical weakness. We always made a point of having someone stand near the Priestess to catch her at the end of the DDTM in case she lost her balance. I always felt as if I had to fit back into my skin. And it's also common to be really hungry for certain foods. (When I drew down Sekhmet I wanted LOTS of meat!)
I am not going to teach how to do this on an open board or with people I can't work with directly because I have safety concerns for people who might try it and get in trouble because they aren't properly trained. In addition, I would have to work with someone for quite awhile before I was certain they were ready to do this. In my own Tradition this is something done only by 3rd Degree Initiates and one does not reach 3rd Degree in my Trad until after 7-10 years of training and ritual work. But I hope that what I have written gives you a better idea of what DDTM is all about.
If you have any specific questions don't hesitate to ask me.