efficient training depends on many factors: number of spawns, how often you get into a fight, how often they kill your pets, how often you have to stop to get healing foods(or not, if you have a e-remote water), etc. you gotta consider these factors when choosing a place.
example: Oslya is a good place to train, especially on raptors, because you get good meats often and you can pretty much auto-heal without running out of them, BUT, if you train outside, you risk running into random drowcrushers that can break gears, and if you train inside caves, you won't get drowcrushers, but you'll get more mobs per battle and your pets could die more often. you'll probably have to figure some of this stuff yourself, since that would be too much to ask of an already detailed guide.
btw, thanks Kojika