Note 1
At every store the very first thing a cashier asks you in Spanish is if you need a fiscal check (it’s done for business expense deductions). Say “No”.
Note 2
It’s normal here if the boy who bags your products will help you to bring the bags to your car and load them. Usually we give them 50 pesos / $1 tip, or we take the cart from them after bagging and do everything ourselves for free.
Note 3
All prices in the shops already include all taxes which would be a breath of fresh air for our Canadian friends 😉 The only exception is the restaurants.