There is no perfect answer but I have shipped many games as a buyer and seller.
1. Look at their history and ratings on Pinside. Get a feel for them if it helps you.
2. Seller determines method of payment, period. It’s up to the buyer to decide if they are comfortable with it or pass. I personally prefer back transfer aka wire. It’s fast and reliable. I offer an email receipt of transaction.
3. As a seller, I offer demo pics of how I have prepped games in the past and offer a choice of pallet or legs on. I always wrap and prep myself. Regardless of how a shipper advertises, it’s what the local guys actually do to the game. Many times for me, “white glove” was a driver and some local guys they gave $20 to help the driver load it on the truck. If a seller tells me they the shipper wrap it, I pass.
4. Lastly, the buyer is actually shipping a game to themselves. Once it leaves your house, it’s their game. As a buyer, I ensure for all I need and get pictures. As a sell I provide many pictures and recommend good insurance.
It sounds like a bit of work, but it’s really no trouble and has been reliable for me.