The first way that you do is not easy to believe what other people say. if you want to try, look at the person's history. if it has a reputation of trust then chances are it is true. everything you can do with a good track record.
But past record alone will not help to prevent getting scammed. Because there are a lot of incidents that some trusted people turned scammers overnight. Engaging escrow and dealing in multiple times by dividing the total amount into small parts are few of practical way to safeguard ourselves from not getting scammed.
I always do prefer to go for currency exchange with only small amount even in the case of going through escrow. That amount is affordable to lose in worst case.