I make my own tinctures. Can I recommend a good book to you.
Making Plant Medicine by Richo Cech.
I study quite a bit of his work and he is an amazing herbalist.
His business
http://www.horizonherbs.com is where I purchase many seeds, and root stock.
I grow some of my plants and wildcraft what I can as well. I have a desire to understand LOCAL herbs in case of an emergency (such as gas prices get so high that trucking doesn't happen and a depression starts to incur-ya know stuff like that)
and then trying my hand at developing an herb garden here with herbs that dont grow wild here that my family finds essential~
Good luck.
One trick that has helped me make better medicine is blenderize it with your menstruum. Breaking up the plant matter in the blender has made stronger extracts for me.