Don't do transactions or even opening a wallet if you're not in a proper state of mind or half asleep, people tend to do this to check their wallet, emails and accidentally click something and draining their wallets or send a wrong address btc/alt, even when you're mad or sad.
I have read about a lot of such incidents that occur because of little mistakes made by those who are either drunk, half asleep, or trying to conduct transactions when they are in a hurry. It's crazy how little distraction and mistakes can cost a lot.
Another warning that we should also take very seriously is never to try to use a wallet option that we are not familiar with. Some people have tried to adjust fees and end up using the amount they plan to send as the fee and the fee as the amount they send to the receiver.