hanging/securing a stable door

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Martin Carroll saying something like:

First, make sure the horse is long gone.

There are two normal approaches here. One is to temporarily fix the two bits together (including a spacer between them), and then hang it as if it were a single door - although with 4 hinges instead of two or three. The other is to hang the bottom bit first and then use it to support the (on a spacer again) while you hang that.

Its important that if you need to "shoot in" the door, that you do it treating it as one door rather than two halves - or the result will never look right.