Avoiding ticket snafus?

[mournlight]

Preparing an email for my camp's upcoming DGS purchasers. It includes tips such as:
-Check your email (the "correct" one that you used for your profile!)
-Check spam if you don't see the expected email
-Make sure you can log into your profile
-Check your profile for Sparkly Things
-Notify your bank there will be a large transaction, possibly out of state
-Don't wait until the last minute to purchase so that there is time to correct problems
-Be prepared to use a computer versus "just" a cell phone or tablet

Other tips? Seems like I'm leaving a few out that caused issues in the past, but I'm drawing a blank.
See everyone soon!

[ken]

Each credit card can only be used for one transaction. So if a campmate is buying tickets for others, they need to use a different card.