Choosing the flower remedies is an art in itself. While there is, in my experience, no substitute for knowing each one thoroughly, I have noted something interesting. If you take a couple of drops direct from the stock bottle, the more you need the remedy, the stronger the taste will be. It is possible to take the same remedy at various times, and sometimes not taste anything, while at other times, your tongue will tingle as strongly as putting a nine volt battery on it. (Though, certainly not as unpleasant.)
This, of course, flies in the fact of mixing them up first, and you are ingesting pure brandy. I have noticed the same effects if they are mixed into water, however, it is very subtle. It seems that it infusion into the alcohol seems to give it some additional quality.
Other methods.
Some people use methods such as divining by a pendulum or kinesiology (muscle testing) to choose the right remedy for people. As someone who had had this done to for over a year, I can tell you it's not a very effective, or accurate method. With kinesiology, it is said that your body doesn't lie, though I have to say, in my experience, this isn't the truth.
As a side note, some practitioners let you choose the remedies and use this as a guide to what your problems might be. However, they tend to concentrate to the negative aspect of the remedy. If what they tell you doesn't feel right, then it most likely isn't!