Have you heard of Privacy? It's an app that sets up virtual credit card numbers and you can specify how much or how many or how often that number can be charged. I mainly use it for "free" trials that want a credit card to bill if you don't cancel after the trial period. I set a $1 limit so the company thinks it's a real card when they do the small feeler charge. Saves me the hassle of remembering to cancel.

You can obviously use it for other purposes, like when you might be dealing with an iffy vendor.