I've shopped at Costco for over a decade. Here are the 8 biggest mistakes I see customers make.

Costco is a great chain to affordably buy products in bulk.

Olivia Yi

• I've shopped at Costco for over 10 years, so I know a lot of the rookie mistakes to avoid.
• Knowing how to read the chain's price tags can help you make smarter purchasing decisions.
• Costco often has great deals on restaurant gift-card packs and its house-label products.

After over a decade of shopping at Costco, you can say I'm quite a fan of the chain.

I run a recipe blog and social account...