Make sure you use a true essential oils and not a fragrance oils as these tend to contain a number of synthetic chemicals\additives, which are not generally listed on the labeling and are generally not suitable for use on the skin.
Here is a link to a couple of good articles which explain the basic about " Blending Essential Oils" (http://aromatherapyandnaturalskincare.com.au/index.php?essential_oils=188) and "Aromatherapy Perfumes" http://aromatherapyandnaturalskincare.com.au/index.php?essential_oils=189&Aromatherapy%20Perfumes)
The key to making a good Perfume\Cologne are the "Notes" of the essential oils. This means that the blending is the key to making a lasting perfume, one that smells balanced at the beginning and continues to do so as the various molecules dissipate. The best blends will usually contain a mixture of all three notes, although it is possible to blend just top and middle notes (lighter and shorter lived) or middle and base notes (heavier and more intense). It is rare that a top and base note will blend harmoniously, although it can sometimes happen.
- Top notes are the lightest, with smaller faster moving molecules. They evaporate very quickly, so will dissipate first and often appear more obvious when you first smell a blend, then gradually disappearing. Top notes generally have a brighter, lighter energy. Typical top notes are the citrus group of oils, which reflect this bright lively character.
- Base notes are at the other end of the spectrum. They have heavier and slower moving
molecules and take much longer to evaporate. They will inform the character of the blend after the other notes have dissipated. Base note oils tend to be slower, often warmer, often more relaxing. Many wood oils, such as sandalwood, are base notes, but this group also includes very different oils such as ylang ylang and ginger.
- Middle notes are, as the name suggests, between top and base notes in terms of their energy and volatility. They are often very balancing oils, although some can be relaxing and some stimulating. Many herb oils fall into this category, such as lavender, rosemary and marjoram.
Hope this helps!
· 8 years ago