The idea is simple: Run a fort as normal, preferably on a very small embark for FPS issues. Keep going until you manage to capture a male and female dragon. Check legends first to make sure there's a living male and female available. Mod them to be [PET]-able, and tame them. Egg-layers won't breed unless tame, sadly. Once acquired, turn off invaders (maybe) and artifacts (maybe) and run your fort for 1,000+ years. Specifically, run the fort until the dragons lay an egg, it hatches, and that hatchling matures to full size after 1,000 years.
Of course, this IS a dragon we're dealing with... It needs a proper horde once it matures! To that end, the caravans and renewable resources are to be exploited to fullest extent. Import gold and platinum and the best gems, and make endless crafts and chests and bins, and of course statues and other adornments, to provide the first domestic dragon with a horde of treasure.
Quoting myself from another thread:
Tools:
9,001 barrels
Farm plot set for plump helmets, sweet pods, pig tails, and dimple cups.
Farmer's shop, dyer, loom, and clothier.
A good waterfall and dining hall.
Now: With that number of barrels and a single still, you should hit the Booze Singularity Point, where you can set the brewing job on repeat and the amount of clutter will ensure that it never stops. Eventually, the clutter of barrels in the still will slow down production until it reaches the same rate as consumption, no matter how many dwarves you have. The Sweet Pods + Plump Helmets helps ensure that booze is never stale, and that the pods can always be brewed even if the helmets are all eaten.
In the meantime, produce ~100 thread, bags of dye, dyed thread, and dyed cloth. Once you've "primed" the system with a number of items, then go through the textile production line and set it to /R, as long as the farm produces more than a single shop can go through in a year (a 10x10 farm with a good farmer can outdo a farmer's shop with only 1 season of pig tail production) then the clutter effect should streamline production to make sure nothing ever runs out of resources. Keep this going, and you can automatically produce infinite goods of dyed cloth, and after ~5 years you should have legendary skills and produce 1,800☼+ of goods from every "cloth crafts" job.
Of course, that's a lot of goods produced, so you should sell them every year to 1: Make room for new goods, 2: Score up your Exported Wealth, and 3: Relieve some FPS drag.
You should need to merely act once a year to sell goods and check if your brewer/clothier/farmer has died, and the rest of the time it just runs on smooth. That is, assuming invaders and artifacts turned off. Not that invaders are so difficult anyways, and moods can be handled with trade or avoided with a small population.
Trade the sub-par crafts in favor of raw ore and metal bars, with which to make new crafts of higher value. Import GCS silk thread (not cloth) so that it may be dyed and woven by the most dedicated tailors of the world. Harvest the surface and produce an endless stream of clear glass goods, menacing with spikes of high value and adorned with hanging rings of trivial indulgence. Bonus points if you manage to lay gold floor for the growing dragon's horde room and gift the beast with a proper throne and statues and a temple where your peasants may view it with awe.
Additional bonus points if you breed other Mega or Semi-Mega beasts. Only Dragons, Hydra, and Roc lay eggs. Giants, Ettin, Cyclops, and Minotaur may breed while untame, as long as they have the [PET] tag and are on the map with the opposite gender, they will breed. (Although the male may be tame while the female is wild, and the offspring will be wild. I suggest to tame the male and have a minotaur mayor, they are fun.)