A great natural fragrance begins with essential oils. Wouldn't it be great to have the nose of a perfumer? To be able to pick out the different scents in a blend without being told what they were.
Alas, I do not have that nose and must settle for simpler fragrance blends using only 3 or 4 essential oils. Sometimes I become daring and throw in one or two more.Toothpicks are a good tool to use to create scents without using too much of those expensive oils. I just dip the toothpick into the oil and call that one drop. After I have a few toothpicks scented, I put them together to see if I like that blend. Very little essential oil is wasted and if I put the toothpicks in a container, I can come back later to see if I still like the blend or if it needs more work. My best advice is to follow your nose. Everyone has a different idea of what smells good so you might as well make one that you like.
Historically, essential oils were put into catagories based on the musical scale system. This classification process, invented by a Frenchman by the name of Piesse, is still followed today though to a lesser degree. The oils are classified as being a top, middle or base note.
Top notes are fleeting. Their scent is highly volitile but provide that first flush of scent.
Middle notes take longer to notice and provide body to the scent blend.
Base notes are rich, heavy scents that are long lasting. They are slow to evaporate and act as a fixative in the blend.
A table (http://www.soap-making-essentials.com/essential-oils-blends.html) with the oils listed under their corresponding note. Some essential oils can belong to more than one catagory and there are many different opinions as to where each belongs, so treat this table as a guideline only.
For more information on essential oils, go to the essential oils page (http://www.soap-making-essentials.com/essential-oils.html) of the site.