I have to agree with Summer ...
I have boxes and boxes filled with small bottles of each kind of herb, made one by one by the quart or gallon.
If I decide to mix any I do it AFTER each has been made alone. I also like to be able to control what is given and taken. You just never know how each person will react to an herb. Thus giving a mixture makes it very hard to find out which herb is causing a problem ... IF there is one.
I have both elderberry and elder flower tinctures but not mixed together.
I also agree that the better the Brandy the better the tincture. But, I use Vodka for nearly all of mine. I do however use Christmas Brandy for my flower tinctures that only uses mere drops of each flower tincture formula.