Eterna Forest is a good place to train, but if you get sick of that and you want even stronger; Old Chateu is great. With all the creepy GHOST Pokemon plus the legendary ROTOM in the TV.
anywhere.
Some people will argue with me but i think the best place to train is at the Pokemon lugue you can battle them over and over again
There are various good places to train flying types in Pokemon Platinum. A good thing to do would be to use the vs seeker.
Personally, I would train a Bird-Type Pokemon at a place where those types of Pokemon is very effective to it. Like Fighting-Types. They are weak to Bird-Types. So, I would train it there!
in heart gold cerulean cave in platinum i don't know
go in eterna forest and somewhere there is a green rock train evee buy itlevel up eevee at the moss rock in eterna forestor beet two rangers on router 212 one of them uses leafeon
you should train sycher against fire and pshcik pokemon:D
the best place to train at is in enterna forest because when you with Cheryl run in the wild and battle Pokemon i got my ponyta up 6 levels in half an hour from lvl 20 to lvl 26 and you don't have to heal. Other places are route 202 route 217 and between velistone and the resort place just use the vs seeker and keep battling them like the collectors and breeders and others Hoped i helped :)
route 205 for Pokemon diamond, pearl and platinum. the trainers have Pokemon from level 10 to level 17
Train Aron.
You train your Pokemon to lvl 100 or you can find some at the battle frontier in the place where you rent Pokemon and select open level in Pokemon platinum
You need to train an Eevee at Moss Rock in Eterna Forest.