Saw Palmetto is an herb which is reputed to bind to testosterone so that if you have excess testosterone the Saw Palmetto renders some of it unusable (or it may link up with the testosterone receptors so the excess testosterone can not be used in that way)
Vitex is a hormone balancer. It works on the pituitary gland to balance hormones in whatever direction they need- low ones rise and high ones lower. It is a cumulative herb and can take many months to work. It needs to be taken regularily to be able to accumulate. Most women take less than 1500mg per day- some right around that, some less so if the package recommends more I would say stick to under the 1500mg. It can be used throughout the cycle although some like to take a break from all herbs during AF. I take it throughout.
Dong quai CAN NOT BE TAKEN DURING AF as it is a blood thinner and can increase bleeding. It is a hormone balancer as well as a reproductive tonic. I have seen it recommended to take throughout the cycle OR pre o OR post O, so this is a decision you will have to make. I take it throughout while I am annovulatory and then after I started ovulating I take it post O. Some women have concerns about using it post O because it could affect a developing fetus. I have done much reading and research and don't personally consider this a problem as long as all herbs are discontinued upon confirmation of pregnancy.
I have not had good results when I used vitex and NPC together. I personally feel it may be contradictory because I am taking vitex and dong quai to balance my hormones from within and then I am adding an external source of progesterone. My body reacted with longer cycles and I stopped using those together after a few cycles. Others may have had better results with that combination.
There are many women though who have had good results with using NPC to regulate their cycles. A good book for more info on this is called What Your Dr. May Not Tell You About Menopause by Dr. John Lee. He also has one called the same as above except Premenopause.
Some books to learn more about these and other herbs for women are...
Herbal Healing for women by Rosemary Gladstar
Herbal Remedies for women by Amanda McQuade Crawford
The Complete women's Herbal by Anne McIntyre
Overcoming Infertility Naturally by Karen Bradstreet
Infertilty Solutions by Shana Albo
I know you said you are not specifically ttc but these books offer good info anyways to better your cycles. Another book which is very helpful to learn whether you are ovulating or not is Taking Charge of Your Fertility by Toni Weschler
I just wanted to mention too that I have a success story with these herbs. I have a beautiful 7 year old which I would not have had without these and other vitamins and herbs I took.
Best to you in your health quest,

Sheri