I will give you some ideas about the herbs and oils and how you can work with them and use them in your Art.
When one plants the herbs herself/himself, grows them , harvest them herself/himself and make the oils and uses them herself/himself, then she/he is a lucky one ( smile ). But even collected in nature and in wild areas the blossoms are perfect for use, some witches prefer harvesting wild blossoms only.
Oils I make myself are mostly flower oils, I use the blossoms.
First you need to do some research about what you need. Herbal kingdom is VAST and there is always a lot to be learned and explored. When you know what blossoms you need, then go find them. When you find them , put them in a glass jar, fill the jar with base oil like olive oil , sunflower oil, almond or linseed oil. Add a thin/a milimeter/ layer of pure alcohol on top/this tip about adding the alcohol is from a dear sister of the craft / and close/cover the top of the jar well and tight. Write on a small sheet of paper on the top of the jar the date when the oil will be ready for use/count 40 days onwards , use a calendar /. Then put the jar into the sunshine and leave it there for 40 days. The Sun rays will penetrate through the glass and work with the blossoms and oil. The Moonlight will shine on the jar during the nights and charge it with her energies. You can notice how the colour of the oil changes and how some blossoms fade giving their power to the oil. The oil and blossoms will mix and after 40 days you can filter the blossoms and pour the oil in dark glass bottles and store it. If you do not have gark glass bottles, then you can keep the oil in dark and cool place . The oil is ready for use. Do not forget to consecrete it in a sacred circle before using it for magical tasks. Use it for anointing candles, yourself or your magical items.
Now I will mention the qualities of some herbs :
Dandelion – courage, bravery ; Fire, Mars
Clover – fairies, wishes, magic, devas, natural spirits
Lobelia – fairies, love, separation, madness. Be careful when you work with Lobelia, it is always so uncontrollable.
Rose – love, friendship, defence
Chicory – invisibility, obstacles removment
Marigold – Divinity, Wholeness, Sun and Moon, protection
Wild violets – love, wishes, dreams, protection, natural spirits; Friday
Black blossoms – hex breaking, breaking curses, protection
Lily of the valley – stops aggression, protection, promotes psychic visions, devas ; Monday, Moon
Lavender – peace of mind, healing, blessing
Mint – money, good luck, good health; Friday
Until we merry meet again
Blessed Be with inspiration and Light
Mistress of the mountains