Size to the bottle and the cap
Measure the bottle with the cap on, and note the shoulder and cap diameter. The insert holds the bottle at the shoulder so the cap never touches the lid. A single-bottle rigid box usually runs about 4 by 4 by 6 inches; adding vials takes it to about 8 by 5 by 5. Send a sample bottle if you can; it removes the guesswork from the cradle.
Glass is heavy, so the insert does the work
A 100 ml bottle in a 18pt carton bows the panels; that is why perfume cartons run on 24pt and why rigid fragrance boxes step to 1500 gsm at 100 ml and above. Paperboard cradles suit most bottles. Foam suits heavy or oddly shaped flacons, and velvet flocking suits small bottles where the reveal matters.
Restraint sells at the counter
A matte or linen wrap, one champagne foil or blind deboss mark and a centered bottle look more expensive than a fully printed box. Soft-touch photographs well and feels right in the hand. Our fragrance packaging guide goes deeper on inserts and wraps.
Labeling notes
Fragrance sold as a cosmetic follows the FDA cosmetic labeling rules in 21 CFR part 701, including the ingredient declaration, net quantity and the name and place of business. If the outer carton is the package on the shelf, it carries that information. Alcohol-based fragrances also have carrier shipping rules, so check with your carrier before you ship.
This is packaging guidance, not legal advice.