Essential oils are defined in three categories, depending on their evaporation rate.

1. The top notes are light and airy and evaporate quickly. They are the first noticeable scents, penetrating and fresh, lasting no longer than 30 minutes. They usually make up no more than 5 - 20 % of the blend.

2. The middle notes are balancing and soothing to mind and body. These bouquets make up the heart of the blend, 50 - 80%, and may last up to 3 hours after application.

3. The base notes are rich and heavy scented, emerging slowly and lingering. Deep, warm and sensuous, these oils should not make up more than 5% of any perfume blend.

A well-balanced perfume blend has a component of top, middle, AND base notes in jojoba oil. The quantity of the notes used will determine whether the perfume is a heavy oriental scent (more base) or a light floral aroma (more top).

Blending:

Aromatherapy: The Complete Guide to the Healing Art by Kathi Keville and Mindy Green recommends step-by step blending as follows:

• Before you begin, take a minute to focus your mind. Take a few deep breaths, relax and center yourself. Think about the purpose of your blend.
• Keep detailed notes of your experiments, including your failures. Be sure to label each blend with the date, the ingredients, dilution, name of the blend, etc.
• Begin by selecting oils suitable for your purpose. Try to limit oils to 5 or less, until you become familiar with different blends. Remember to wave the cap under your nose, instead of smelling out of the bottle, as many oils are overpowering before dilution.
• Begin mixing SMALL proportions, drop by drop. To prevent contamination, use separate droppers or rinse the droppers in vodka or pure grain alcohol between oils. Allow each dropper to dry before dipping it into the next scent. As you mix the oils, sniff as you go to check progress. It is best to mix the oils together before adding the carrier oil. You may use alcohol, hydrosol, water, or vinegar if you do not want to use a carrier oil.
• For every 5 - 6 drops of essential oil, you will need approximately one ounce (30 ml or 600 drops) of carrier oil for a massage or body oil. For perfume, using an equal amount of jojoba oil as your carrier oil will help extend the life of your blend.

Recipe Ideas (denotes Top, Middle or Base note)
Afternoon Delight 4 drops orange (T) 2 drops geranium (M) 3 drops lavender (M) 4 drops sandalwood (B)	Adolescent Airs 5 drops lavender (M) 4 drops mandarin (T) 2 drops neroli (M/B) 2 drops vanilla (B)	Earth Dew 4 drops juniper (M) 3 drops cedarwood (B) 2 drops frankincense (B) 3 drops jasmine (B)
Floral Spice 2 drops ylang-ylang (M/B) 2 drops vetiver (B) 6 drops bergamot (T) 3 drops cardamom (T)	Kiss-Me-Quick 2 drops rose (M) 3 drops jasmine (B) 6 drops grapefruit (T) 2 drops ylang-ylang (M/B)	Energy 2 drops black pepper (M) 6 drops lemon (T) 3 drops rosemary (M) 1 drop peppermint (T/M)

Scents
Citrus	Floral	Forest/Woodsy	Minty	Spicy
Grapefruit Lemon Lemongrass Lime Melissa Neroli Orange	Benzoin Broom Jasmine Rhododendron Rose Tolu balsam Ylang-ylang	Eucalyptus Fir grandis Sandalwood Silver fir	Patchouli Peppermint Rosemary	Sage Star anise Tulsi