An easy way to blend oils is in batches of 100 drops. This allows you to easily work out the percentages of each oil in your blend ahead of time. It also makes for easy calculations later on if you'd like to increase the recipe size. 100 drops will give you about 1 teaspoon of blend. This is enough to create an approximate 2 percent dilution in an 8 ounce or 1 cup measure of a carrier oil (such as skin care oil) to create a body, bath or massage oil.
Blends that include a balanced array of top notes, middle notes and base notes will be most successful. Essential oils are complex and can contain dozens of individual aromatic compounds. For instance rose contains about 100! These compounds all evaporate at different rates. If an oil is made mostly of compounds that evaporate quickly, it is called a "top note" oil. If an oil is made mostly of compounds that evaporate very slowly, it is called a "base note" oil. "Middle note" oils contain a diffusive, rounded aroma at their core. In blends, middle notes serve to bridge top notes and base notes.
Strive to create blends that have a harmonious balance of all three notes. For example, if you would like to create a rose-scented blend, you could use rose otto or absolute as the middle note, lemon as the top note and myrrh as the base note. The lemon will extend the rose and open up the scent, while the myrrh will slow the evaporation and "fix" all the components into a cohesive whole.
To blend your oils, measure the drops into a small, bottle or vial. For convenience, simply use the dropper insert that the essential oil bottle comes equipped with. Breathe deep and assess your response to the aroma, then adjust according to your preferences.