Using fragrance formats
How to use a 5ml perfume decant
Use a 5ml decant according to its container and product directions, keeping the claimed source identity clear. Transferred fragrance is not automatically an official sample of the referenced maker.
A HUME Fragrance buying guide

Read the applicator
A spray and dab vial deliver differently. Do not copy counts from another container as equal quantities.
Observe the complete scent
Record later development and preference rather than using a first sniff to certify origin.
Match any later purchase
Save maker and version before buying more. A similarly named interpretation is a different product.
Try this before you buy
Write the decant's exact claimed source and applicator before beginning a wear record.