100ml of each:
Perfumer's Alcohol
Benzyl Benzoate
Di Propylene Glycol (DPG)
Diethyl Phthalate (DEP)
Virgin Jojoba Oil
MCT Oil (Fractionated Coconut Oil)

Start by making a 10% dilution of one of your existing aromatic materials in each solvent. Same material, six carriers, six blotters. The differences in character, throw, longevity, and feel will tell you more about how solvents work than any amount of reading.

As a general guide:

For spray perfumes and eau de parfum: perfumer's alcohol is the correct base. Dissolve any powder materials in alcohol first before incorporating into a formula.
For reed diffusers and room sprays: DPG or a DPG and alcohol blend. DPG alone gives slower, more sustained diffusion.
For oil-based roll-ons and body oils: jojoba for a skin-close, absorbed finish; MCT for a lighter, faster-absorbing feel.
For thick or resinous materials that won't pour or blend easily: benzyl benzoate or DEP as a pre-diluent before incorporating into a formula.
For fixing and extending a blend: benzyl benzoate and DEP both slow evaporation and anchor lighter materials.

Typical working dilution for evaluation is 10%. For skin application, 2-5% in a carrier oil, or follow IFRA guidelines for the specific materials in use.

All solvents in this bundle are for external use only. Do not ingest. Keep out of reach of children and pets. Avoid contact with eyes. Some individuals may experience skin irritation with prolonged or repeated contact, particularly with DEP and benzyl benzoate. Patch test before wider skin application.

Perfumer's alcohol is highly flammable. Keep away from heat, sparks, and open flames, and store in a cool, well-ventilated place away from direct sunlight. All other solvents in this bundle are low-flammability or non-flammable under normal storage conditions but should be stored tightly sealed in a cool, dark place regardless.