4–8 items is the sweet spot. Below 4 items, base shipping isn't amortised efficiently. Above 8, QC workload and customs complexity increase.
Use the 90-day warehouse window. CNFans, Kakobuy, and Sugargoo all offer 90 days free storage — order items over 2–3 months and consolidate before shipping.
Economy line saves significant money. A 3kg haul on economy (¥96) vs express DHL (¥360) saves ¥264 (~$36) — often more than the service fee on the entire haul.