Almost everything on this site is safe to do. A candle, a bowl of water, a stone from a windowsill and an hour to yourself are not dangerous. The handful of things that can hurt you are worth knowing before you start, and they are short enough to read in a minute.
Most of what goes wrong in this craft goes wrong here. Candles belong in dishes, on a surface that will not burn, away from curtains, paper, hair and anything that moves in a draught. A rite that asks you to leave a candle burning overnight is asking for something you should not give it. Put it out, and light it again tomorrow.
Charcoal discs for incense burn far hotter than they look and give off carbon monoxide. Use them in a heatproof censer with sand in the bottom, and open a window.
A plant being traditional does not make it harmless. Comfrey damages the liver when taken internally. Rue blisters skin that afterward meets sunlight. Mugwort, pennyroyal and several others are avoided in pregnancy. St John’s wort interferes with more medicines than almost any other plant, including hormonal contraception.
Every entry in the A–Z herb guide now carries a note where there is something to say, and nothing where there is not. Read the note for the plant in front of you rather than assuming. If you take any regular medication, ask a pharmacist before you swallow a herb you have not taken before — they will tell you in a minute and they will not mind being asked.
Do not gather from the wild unless you are certain what you have. Several useful plants have relatives that will hurt you, and the classic mistake is confident rather than careless. Check, too, what is permitted where you live before cutting anything that is not yours.
Essential oils are concentrated to a degree that surprises people. They are diluted in a carrier oil before they touch skin — a few drops in a spoonful, not neat — and they are not swallowed. Citrus oils in particular can burn skin that afterward meets sun. Keep the bottles away from children and animals, who are far more sensitive to them than you are.
Some stones dissolve, corrode, or release something unpleasant in water, so a stone is not put into anything you intend to drink. Nothing on this site asks you to make an elixir. Do not cut, sand or tumble stones at home either: the dust is the hazard, and some of it is genuinely bad to breathe.
Lilies are lethal to cats. Every part of a true lily or a daylily, including the pollen and the water it stood in, can cause fatal kidney failure, and a cat brushing past a vase is enough. Mistletoe, and several essential oils, are also poisonous to cats and dogs. If you keep animals, that decides some of what comes into the house.
Nothing here is medicine and nothing here treats an illness. The beauty and health workings on this site are symbolic — they concern attention and self-regard. If something in your body is wrong, see a doctor, and go early rather than late. A rite is not a reason to wait.
The same holds for a mind under strain. If a night is going badly, tell a person, not a candle.
Some of the older material on this site is aimed at other people, and the argument about whether that is acceptable runs through the whole collection rather than being settled at the top of it. What is worth saying plainly is that nothing here works as a substitute for speaking to somebody, and nothing here is a reason to act against a person in the ordinary world.