Here are a few tips to keep in mind:
Know what’s restricted or what must be declared at the customs. Check handicrafts made from raw materials carefully, including woven plant products (mats, bags, placemats) — don’t buy items showing signs of insect infestation or damage.
Wooden items — avoid souvenirs with holes (a sign of insect activity), and items with bark on them. Animal skin products, including drums must be declared, and may require treatment.
Products made from seeds, including juggling and stress balls, necklaces and bracelets must be declared for quarantine inspection (and may be treatment) when you get home. Don’t bring food home, including pet food and plane food. Beware of claims (on packaging or by vendors) that products meet Quarantine / Import requirements. They often don’t. If you plan on sending your shopping home by freight or mail, declare the contents accurately – penalties will apply for incorrect declaration. You may also be charged for a quarantine inspection.
Be aware that all international mail is screened, and that your items might need to be inspected and/or treated (at a cost).
Check if you are buying designer copies of shoes, bags and watches off the streets as this is a crime and is punishable with a fine in some countries.