The ultimate goals for shape & structure in Apple trees are either a mushroom shaped tree; wide & low or an open tree; you can throw a hat through the branches. Branches should be growing 12 - 18" apart.
Pruning rules for branches growing under, up, down, and crossing:
Under: leave room to work underneath the branches of the tree to hoe, weed, and trim the grass. Never let sprouts grow below the graft of the tree (base of the trunk).
Up: Cut all branches growing straight up (except main stem)
Down: Cut all branches growing straight down
Crossing: Cut all branches that touch each other when by crossing over each other; this closeness could lead to injury & disease