Since no one seems to think about how this could have prevented, here is a simple way, which I've applied to lots of things in life, not just cryptocurrency transfers:

- If you're making a transfer somewhere with a large amount, do a small transfer first and verify it's working. Confirm at the receiving end before moving big sums.

- If you're calling a contract, try it with a small amount first. Verify the parameters multiple times, and verify the return values multiple times.

- If you're doing something with a huge sum of money, do it in steps instead of all-at-once. Fees won't be as big since you're already dealing with a huge sum of money anyways

- Verify verify and verify that everything went alright with the small sum before trying to do something with a big sum

- If you're tired, don't do it. Wait until you got some sleep

- If you're rushed, don't do it. Wait until you're not rushed, have a tea and think about it

- When in doubt, verify it and don't be tired

- If you're not an expert, have someone who is do verification above for you