On
apple seedlings:
I'm randomly tossing some seeds into hedgerows. I've certainly appreciated foraged fruit from wayside
trees, so I'm adding some for future generations. Other fruit too. You tend to get something with qualities from its parents - so I favour seeds from my own apples over the mediocre bought jobs.
To encourage earlier fruiting, it apparently helps to encourage downward growing - to this end I've paired up seedlings and bent each of their leaders down, and tied it against its buddy's stem, pruning off unnecessary upward twigs. Only done that this spring, so a while before I'll see results. This technique apparently applies to all trees and climbers - it tells the plant it's got high
enough.