If you cancel the free trial as soon as you start it you normally still get the full trial so nothing to remember!

Shoutout to Shudder, a streaming service for horror movies/shows, that doesn’t confirm payment at all besides making sure it’s a real card.

I’ve been using 10minute email and a gift card with 13 cents on it to make free trial accounts for more than half a year work no issues

With Amazon at least you can contact them and ask for a refund if it’s just one or two days after the payment, it has worked twice for me (genuine mistakes of mine)