What is the proportion of essential oil that can be added to a carrier oil ?

I recommend going to a practitioner who is qualified to practice aromatherapy treatments and have them advise you on what proportions to use. They may even be able to suggest a more effective application and other oils for you to try. It would depend on what you’re going to use it for, how much you want to prepare at a time, what kind of quality oils you have (which the practitioner can also tell you), and so on. It takes very little – a matter of drops – and I don’t think that too much can really harm you, but why use more than you need when good essential oils can be expensive?

Clove oil is a great analgesic and it will help warm your body when used in a bath or a massage oil. It is very potent and you should only use 2 drops in bath water and only 1 percent in massage oils. Cinnamon is also very strong and should be used sparingly, no more than 2 drops in bath and only 1 percent in massage oils. using both clove and cinnamon together is not recommended as it can be harmful to sensitive skin and the scent may be too strong and cause a headache. Basil would mix OK with either oil and can be used at 2 percent for massage oil, however prolonged use is not recommended. I would recommend mixing 2 drops sweet marjoram, 2 drops lavender and 2 drops rosemary to bath water or 1 drop sweet marjoram, 2 drops lavender and 2 drops rosemary to 2 teaspoon of sesame oil for massage, these oils are safer for you skin than the ones you mentioned just do not use this blend if you are pregnant or have epilepsy. This blend is also warming and will help with circulation especially in the hands and feet. When using essential oils it is always recommended to start with a little, not all oils can be mixed the same strength, a safe rule is 1 drop of oil to 1 teaspoon of carrier oil and once you see how you handle this you can increase the amount but never add more than 3 drops per teaspoon of carrier oil.