I had my 1st PP cylce at 27 mos pp, so don't give up hope yet!!
From most herbalists perspectives that I've read, teas are just flavoured water unless the herb steeps for over an hour. Tinctures are more like concentrated, thus they are more effective. However most will contain alcohol, so if that is a problem, go the dried (pill) route.
My Naturalpath told me to take 30 drops of tincture a day in a glass of water. I'm not sure how many ml that is. She said that if the taste really bothered me that the pill was also available.
From what I hear, the pills and the tinctures are all available in different strengths so read the label for recomended dosages. As for brand, I got mine from my NP, so I can't tell you what's good and what's not. Just use common sense and buy from a name your trust. You want to put good quality herbs in your body, not alot of junk!
Keep in mind that it is a slow working herb....personally I prefer this over the "quick fixes" of modern medicine as it is easier for my body to handle.