Remove black soot from the inside of candle glasses as it is flammable and will ruin your day if it catches fire
Keep a metal tray or other fireproof surface on your altar for placing free-standing candles (those without a holder)
Never consume fragrance oils, essential oils, or burning oils (Food-grade absolutes are a great alternative)
Try to avoid burning anything with pets in the room (especially if they are of the avian or reptilian variety). If you are going to burn something, do so in a well-ventilated room.
Never burn Cedar in a room with pets, no exceptions
Add a small amount of isopropyl alcohol to any river or sea water you make keep on your altar to slow the growth of bacteria
In leu of a dedicated oil burner, scented oils may be added to lit unscented candles to give a similar effect
Massage oil candles exist, give them a look
Do not eat any foraged material unless you are absolutely sure of what it is and it's ediblity
Sticks and drift wood used for crafts can be sterilized by heating in the oven for 2 hours at 250*f (120*C), check on it often to watch for burning
Honey, oils, wrapped chocolates, and high proof alcohol are great long-term food offerings
Pretty much every handy-craft can be used for magick, including but not limited too: metal working, wood working, sewing/embroidery, book binding, gardening, pottery, etc.
Non-witchy books on meditation, gardening, yoga, foraging guides, medicinal plants, and history are great sources of information to round out your practice
Ethically scavenged or harvested animal parts are okay to use in your practice, never purchase any bat specimens as thay are almost always killed purely to be a specimen (as opposed to deer which may serve as food and the left over parts sold)
Bless clothing you wear often for protection
Never place any of the following in direct sunlight: amethyst, kunzite, smoky quartz, jade, lapis, aquamarine, citrine, and rose quartz. There are many more so when in doubt, look it up
Never place any of the following in water: selenite, malachite (turns toxic as it can be absorbed into the skin), moonstone, tourmaline, desert rose, amber, hematite. Once again, there are many more so do your research.
Random stones you find can work just as well as crystals
Have a separate set of utensils, pots and such if possible strictly for your herbal creations (another set should be used if you work with poisonous plants as well)
A good pocket knife is any practitioner's best friend
Beeswax candles are cleaner burning than paraffin and bamboo charcoal blocks are (reportedly) cleaner burning than charcoal
Instead of wild bird feathers; purchase chicken, pheasant, goose, duck, and turkey feathers
If you want an item that is considered strictly apart of a specific culture, see if people of that culture willingly sell them. Many indigenous groups have lost business because people are too afraid to purchase from them for fear of being called out for cultural appropriation.
While "classical" correspondences exist, they are not a set in stone thing. Make your own correspondences within your practice.
Be inspired by others' practices, but never seek to imitate as you will lose sight of what it is you're trying to accomplish
Incense ash, charcoal ash, burned herbs, salt, and other spent ingredients can be added to black salt (or goofer dust for my hoodoo practitioners)