In order for YA characters to save the day, slay the beast, or kiss the boy, parent supervision must be at a minimum. A lot of YA authors employ one plot device or another to get rid of the parents, here are some of my favorites.
1. Make all the adults disappear (actually haven't read this book yet, but it's sitting on my bookshelf), but I thought it was a great way to get rid of all adult supervision.
2. Parents get killed by an evil wizard, forcing main character to live with an aunt and uncle, who make him sleep in a closet.
3. Set the book during a war, and send the kids off to the countryside to live with a crazy uncle who owns a trippy wardrobe.
4. Make the kids orphans with an older brother who has to look after them, but make sure the kids have cool names like Sodapop and Ponyboy.
5. Have parents bitten by zombies
6. One parent dies and the other becomes emotionally unavailable leaving child to a)take care of other siblings or b)fend for herself with very little adult supervision.
7. Both parents die and child goes to live with work alcoholic aunt, who lives child alone a lot.
8. Child goes to live with other parent to give her mom time with new husband. Father works a lot and doesn't really know how to talk to his child, but gives her a really nice truck. Okay maybe not a nice truck, but it's still more than I got at 17.
9. One parent is murdered and in order for them to stay in the same house the other parent has to work at a job that takes them out of town a lot just to pay the bills.
10. The parents are mad scientists who spend all their time in their basement working on scientific experiments that may or may not include giving their daughter super powers.
10a. Main Character does something horrible and the parents disown him (my next book)
Feel free to add your favorite way to get rid of the parents or guess what books mine came from.