I’ve been thinking about this and I honestly haven’t been able to come up with a good way to safeguard this, or have criteria that would completely eliminate the risk.
But personally, I have done tons of trades, well into the double digits, and have never been scammed. Seems that the grand majority of people on the forum are integrous and trusting. But, never hurts to be uber safe. The most definitive way I’ve been able to vet people is by looking at their past posts, getting a vibe from them that way. Looking through tons of their posts across their time on the forum has helped me massively in discerning who to trust and who to not trust.
Another alternative is if one person trading has been around the forum for a long time, contributed a lot, etc, they are obviously not very likely to scam for a number of reasons, but even a selfish reason of not wanting to be exposed to the whole community & have their whole account banned. So if it is questionable, this method is great!