Oils have been used as curatives for thousands of years and they have been used as a part of religious practices for just as long. Oils were used as preservatives to keep the body until burials could take place. They have been used in medicines as lubricants, muscle relaxers and laxatives. Scented oils are very important in cures and ritual as well. Many times oils were made of botanicals and purified animal fats and oils collected from plants. It was time consuming work to extract purified oils from the source and the herbs and flowers and resins used to perfume them were rare and costly. That is the point of the tale of the fallen woman who anoints Jesus feet. Judas tells Jesus off for allowing the woman to use the oils because they are costly and he feels that Jesus is indulging in some selfish vanity by allowing her to anoint him. Oils were mostly used by the wealthy and Jesus was supposed to be living the life of poverty and suffering.
Today, there are many types of oil that we call perfumed oils. Witches and Wiccans and Pagans of all traditions are renowned for the purity of their oils and the materials they are made from. Even if you are not a practitioner of any magikal art or tradition but you enjoy making wax candles and soaps and lotions with wonderful scents in them, then buy your goods from metaphysical shops. There are also the kinds that you find in art and hobby stores and even at your local shopping center or grocery. These are usually just fragrance oils that you put in simmer jars or on sachets to perfume a room. These are often artificially scented and use a petroleum oil as a carrier. Petrolium oils are like mineral oils or oil for your car. They are made of the same oil that is pumped out of the ground and refined to run our cars. It is not natural and is not good for mystical purposes in most regards.
There are some mass produced brands of essential oils. Spiritual Sky is a popular one and can be found in most "head shops" or hippy stores. It simply takes time to find those dealers who sell the real deal. The most important are Myrrh, Sandalwood, Amber, Dragon's Blood, Lavender, Peppermint, and Cinnamon. The corresponding incenses are great to have, as well. If you need to make potion and need a carrier oil, use sweet oil, or almond oil. If all else fail, use extralight, extra virgin olive oil or corn oil or sunflower oil. They may have a bit of an odor but they work well. Sweet oil can be found in pharmacies or grocery oils.
Now, I know that you see people drink potions all of the time in movies and shows, but do not drink your potions. The potions you make are to be used in the following ways: You may anoint candles with them. The way to anoint is that if you want your spell's desire to come to you. you anoint from the top of the candle to the base of the candle. If you want to the spell's desire to get away from you, you anoint from the bottom up. You may anoint a person with them. If you are bringing them into the Craft, for instance, you would want mix a potion used for dedication. Or if you were healing them, you might want to gently massage the afflicted area. You can use it as a fumigant. You can thin the potion by adding a teaspoon of whisky (or if you are a minor, rubbing alcohol) to every two ounces of potion and sprinkle or spray the potion in a spray bottle around the room to bless or exorcise or to bring healing, whatever you happen to be doing. You can simmer the potion in a simmer pot to incense a room. You can also add herbs and flowers to you potion as they are called for or if they match the energies of the oils you are using.
This is by no means comprehensive, in fact it is pretty basic. So, the next time, I will give you a book list that will help you study into your second and third degree. Some are written expressly for young people, which are still good for the adult novice, and some have a revolving value that comes with reading and rereading the books as you advance in your studies.