rather than make an "official" trade proposal, it is a common
procedure to send a Geek Mail listing your trade proposal &
once both sides have come to an agreement to make it "official".
That's what I've been doing. We agree on what we're trading, I though we'd just meet in person at this point, but he mentioned something about setting up a "trade" (presumably on BGG). Sure wish I was more tech savvy than I already aren't.