Almonds and apricots need some pruning to generating new fruit producing wood. But since the wood will produce fruit for more that one season, often just pruning for structure is needed. I know of a tree near where I live that is judged to be a hundred years old that is producing nicely with such basic pruning.
Cherries and plums only need structural pruning. They just keep on producing without regard to what we do to them.
Judging the expected leaves of a tree is the hardest part. You can't rely on guesstimating based on a the before and after profile until you have a fair amount of experience. You can make a good guess by looking at the pile of limbs and comparing it to what is still on the tree. Just remember to compensate for how tightly packed the pile is.
And as a final note, remember that it is best to prune the tree less if you have any question. You can always prune more later if you need to, but you can never prune less.