Just like real MMO's, MonBre does afford different Styles of Breeding: ie, raising your monsters. I've called them "ways" in loving reference to Guild Wars.

Workerway

If you want to farm some money up quickly, grabbing some workers and making use of the sell function the hatchery is definitely a good way to go about it. Grab however many monsters you're willing to, probably still saving one slot for the 'exploring' monster. (if you want to explore, continue the story, etc.) Use the workers and always do the hard work. Even if you get injured, these monsters are expendable and you won't get injured for too big a length of time. You should set your trainer skill tree up for working completely; don't half-ass it, old man! As the monsters get stronger, they'll be injured less, and depending on their stats and what work you do, you might even get bonus cash. After all is said and done, (the monsters are old and fat, or you are close to your projected money) you then sell them back to the hatchery. This whole process will net you a healthy amount of money in what could be a week's time, as your monster must be at least a child in order to sell them back.

Deathway

Vael's favorite. It's completely based on equipment. The suffix 'of Death' totals your complete defense to 0, but multiplies the +attack of the equip by 2x. So if you have a +10 attack equip, it's now +20 attack. Not too good, you say? The trick is to add another equipment with 'of Death' on it, and the defense will still be 0, but your equip will get 4x the attack, plus whatever the second equip you just added is. So let's say you have two of deaths with +20 attack: that is now +80 attack. A good constant ganker for this type of equip is the worker who can use the quick attack ability for just that little extra boost of attack, while not sacrificing much energy. The monster you are raising should have high luck, strength, and stamina. The luck will add to strength and increase your chance of critically hitting, the stamina will keep you alive through mob abilities, and obviously strength makes you hurt them more. Optimally you'll also want as high stats as possible, so having high mood/health and getting the Battle-Hardened skill will only help you.

FINALLY: you can find death equips on various mobs, but you also have a chance of meeting the death merchant in the wild if you happen to have the... requirements to attract him. As further ownage, you can try to find a natural equip that has the prefix 'cruel' and suffix 'of Death' on it, if you are lucky enough. Oh and please keep in mind your cpower will not be very high with this build, but you will be killing quite tough monsters: this is enough to surpass the 'you are too strong' message and get full SRP.