I’ve never seen this written about in pruning manuals, but many varieties of apples are very reluctant producers of lateral branches with most of the new wood coming off of scaffolds in the form of upright shoots.
These shoots left to their own device will clog up the tree with vegetative wood if they aren’t dealt with. I read of people turning such shoots into fruiting spurs by repeatedly cutting them back during the growing season, but this doesn’t train a tree to a nice shape of well branched out scaffolds so that three branches send out enough secondary and tertiary wood to harvest the full circle of light.
I manage mostly free standing trees where this is the goal and I accomplish it by carrying electric tape with me while dormant pruning and spend a lot of time pulling uprights to horizontal and taping them to another branch to hold them there when I’m pruning uncooperative varieties. I even keep extra branches just to have a point to tape these laterals to- using them as a temporary frame, mercilessly cutting back these redundant branches so they don’t steal too much light from the permanents.
The best shoots to use are those emanating from the side of scaffolds, but sometimes most form on the top. Use what you have to work with. Sometimes the tape is unnecessary when branches can be pulled below existing branches and held there by another branch alone.
On the most vigorous varieties I also often tape upper tier branches below horizontal using lower branches to fasten them to. This will coax a young excessively vegetative tree to earlier fruiting and help calm down the upper tiers.
I’m sorry if this description is inadequate to clearly explain the methods, but I don’t have the means or the time to create a you-tube video on the subject. I developed this technique without the help of even a description like this, so I thought it might be helpful to a couple of you to at least explain my method because it took me about 15 years to figure it out and I find it very useful- even indispensable in training some of the varieties I grow.