In Catching Fire, the Victory Tour starts with District 12, then goes down to 11, and seemingly in order to end at the Capital. Of course, that makes sense for a victor in District 12, but what would happen if, say, a District 4 won? Would the order be the same?
Yes, the order is the same.
It [the Victory Tour] begins in District 12 and then goes in descending order to District 1, followed by the Capitol. The winner's district is skipped and saved for last. Like the Games, the tour is televised. More information on the Victory Tour and the Hunger Games Trilogy
To quote directly from the book:
Usually it kicks off in 12 and then goes in descending district order to 1, followed by the Capitol. The victor's district is skipped and saved for very last. Since 12 puts on the least fabulous celebration — usually just a dinner for the tributes and a victory rally in the square, where nobody looks like they're having any fun — it's probably best to get us out of the way as soon as possible. This year, for the first time since Haymitch won, the final stop on the tour will be 12, and the Capitol will spring for the festivities. (Catching Fire, chapter 4)