This is just an idea I've been bouncing around in my head for a while, and feel like sharing.
One of the big draws to Gen Ones is that they can breed with any dragon. So I was thinking it might be a fun little challenge to try and artificially replicate that in a higher gen dragon.
The way it would work is you start with two unbred gen one dragons. You breed those, pick one of the offspring, and then exalt all other offspring AND the parents. You can then only breed that hatchling with another unbred gen one, and repeat the process.
You can do this as long as you want (perhaps you're aiming for specific colors), as long as you're sure to exalt all other dragons in the line immediately. What this means is that when you finally do decide to stop, your pedigree dragon has no other related dragons available to breed in the game, and is effectively a gen one.
Lore wise, gen one dragons have to come from somewhere. We just don't know where. A pedigree dragon is basically a gen one that knows where it came from.
There isn't really much use to this; it'd be hard to breed up the rarity tiers in genes and breed, it would cost a lot, and once you start breeding the pedigree dragon to sell hatchlings it loses it's "I can breed with everyone" effectiveness. Mostly, it might just be an interesting challenge and a bit of a point of pride to succeed in getting what you want out of it.
Like I said, just something I've been thinking about.
UPDATE: I've decided to do it.
I decided my first run through is a sort of practice, to work out kinks and figure out exactly what rules I want to use for a later run.