Pruning my apple tree - No, that's not a euphemism

I have little-to-no experience pruning things, but it looks like my apple tree hasn't been pruned in 2 or 3 years, so there was a lot to be done.

Thanks Wikipedia!

After researching, here's what I learned:

1. Prune in February, fruit trees go into latency and they can withstand the stress that comes with pruning
2. Cut off dead branches, water shoots (branches growing directly up), branches growing downward, and crossing branches
3. Don't just cut off the end of a branch, cutting stimulates growth, instead cut everything past the branch or shoot that you want to grow. That will encourage the tree to put energy toward the branches where you want growth
4. Leave a little nub when you cut off branches. At the base of each branch is a ring of wrinkled bark, that's where the growth hormone is kept, and you want to keep that. The growth hormone will help your cut heal. Some people try to cut the branch off flush to the tree, but that leaves the tree vulnerable to disease and rot
5. Don't cut off more than 1/3rd of the tree's branches

http://www.landscapeadvisor.com/how-to-prune-viburnum-juddii/

A healed cut.
https://www.youtube.com/watch?v=ubalH1SJHPk

A cut that's vulnerable to infection and rot.
https://davermfarm.wordpress.com/2011/02/04/repairing-snow-damaged-trees/

The winter of 2017-2018 has been super mild here in Utah, and I'm nervous my apple tree isn't really in latency, but I had to prune and I wanted to do it before the tree started budding. Saturday, February 2nd I climbed up in my apple tree in shorts and a t-shirt (did I mention it was February?!) and started cutting.

Since there was so much pruning I had to make up for, I was super conscious of cutting too much. After cutting what I thought was a lot, I moved on to clearing out other things in my yard. When it came down to it, I think I really just dented the overgrowth and there's plenty more for me to do.