Catscratch & Jordan: Attached is a photo I took on January 3rd last month that provides some idea of the way we do it.
We have farms. We operate on farmer scale. That doesn't mean that we are experts, we just don't have time to do everything just right like a lot of people on this forum do or aspire to do. (God bless them. We just can't do it all like that. I wish we could.) We just keep on plunking trees into the ground and hope for the best. Our adult children help us and they will be inheriting our lands. We plant a couple hundred trees in our coarse soil in the morning and then go at it again the next day.
In the background of the photo, you'll see 2"X4" grid welded wire, which we bought this year for expediency. Also in the photo, you may notice that the tree cages are supported by pieces of conduit. We got those for free from a construction site. In past years, we have used any old fence wire we could repurpose and anything from black locust sticks to fallen pieces of TV antenna aluminum rods to hold up the apple tree cages. We train our trees to be whips initially and put sticks in through the sides of the cages to keep the leaders centered if they get too close to the edge.
I wouldn't recommend our system for guys planting just a few trees that they cherish. We are reforesting here.