When we think of the symbolism of the apple, perhaps the first thing that comes to mind is that of sin, because in the Bible it is said that God forbade Adam and Eve to eat from the tree of good and evil; but Eve, seduced by the serpent, ate and tempted Adam. After doing so, their eyes were opened and they were expelled from the Garden of Eden.
For this reason, many identify it with carnal seduction, desire and sex, and they tattoo a seductively bitten apple, or with a snake curled around it or corrupted and full of worms. But reducing it to this meaning would be simplistic since the forbidden fruit of Genesis symbolizes wisdom.
Symbolism of the apple tree and its fruit
For the Germans, Greeks and Celts, apples gave, in addition to wisdom and knowledge, the gift of immortality; thus the apples of the garden of the Hesperides, those of Avalon, or those of Asgard.
They all had in common the being of gold, so a tattoo of a golden apple can symbolize youth, wisdom, knowledge, immortality and eternal youth.
Paris gave Aphrodite the goddess of love, the apple of discord; Paracelsus considered that, cut in half, it represented the sign of Venus (Roman goddess of fertility), therefore, a tattooed apple could also symbolize love.
The apple tree itself is also a tree loaded with meaning, as it was one of the sacred species of the Celts, getting to be punished its felling with the death penalty.
Also, if you like trees simply for their beauty, the apple tree is very beautiful to tattoo with the branches full of red apples.
And if you want an original drawing, get a tattoo of its beautiful flowers, pink on the outside and white on the inside that, when opened, show the bright yellow stamens, since tattoos of this flower are not very common.
More information - The Crann Bethadh: a sacred tattoo of the Celtic world
Sources - wikipedia,
Photos - wallpixr.com, flickr, fanshare.com