Holiday Gifts for Contractors and Construction Team

We’re nearing the end of an 18-month gut renovation project, due to move in at the end of January. It’s been a high-end project from start to finish, and we’ve been extremely happy with our architects, contractor, and construction team (including sub-contractors). Since we won’t be finished until after Christmas, it seems like the thing to do to give Christmas gifts to the people on our team. Who is customarily included on the list, and what is an appropriate amount to give to each person? Do we give our architects and contractor nice bottles of scotch and tip the construction workers like we’d tip a doorman? What is typical?