I've done wire transfers. Cost a couple bucks but so far, no problems. Even with international transactions.
Have also done cash but I really prefer the exchange to be done at a bank so I can deposit the bills and any counterfeit will be detected by the teller or it's their problem. So far, no problems.
Have also bought stuff from complete strangers who took my personal check. Of course, those worked.
Sold something by accepting a cashiers check from a business that was a complete unknown to me. On that one, we met at his bank which is a major player and I stood at the teller's desk, along with him as the teller made the check out and her supervisor signed the check. No problems with that one either.