Take a picture of your tickets and receipts!

Always take a second to take a picture of every ticket, ATM receipt, invoice, etc, when travelling (and even when not travelling after all).

It can turn very useful if:
* You lose your ticket
* You need to show a receipt that you don't have on you
* You need to contest a withdraw weeks after throwing the receipt
* You want to do some accounting
* Etc.

Taking a quick picture costs nothing and can help