To understand alchemy, you must understand two great truths. First truth: "As above, so below." Second truth: "Everything is one."
These truths teach that alchemical substances are everywhere around you — in field herbs, in human and animal bowels, even in rocks. This is because alchemy is life, and life is alchemy. Once you understand alchemical processes, you will understand the processes of life and the world of nature will become an open book.
Yet alchemy is also knowledge. Does the potion require a flower or a leaf? Where is vermilion found — in the kidney or the eye? These questions are answered by books. Therefore, read both the old masters and new works. Practice your herbalist skills and mixing oils and powders.
However, first and foremost experiment — because the greatest discoveries in alchemy have come about through experimentation.