I mainly focus on mons with tanky personalities (or medium tanky but can take attacks) like empoleon, swampert,etc. Speed is immaterial, better if lesser coz trick room is one of my strategies. Although, some exceptions such as Noivern, Gardevoir(not defensive, but my fav, will be always there) are present for the time being. My team does best in doubles. @Maqqy, we share a similarity here. My EV training spread is also similar to the tankiness I desire. It's mostly like this 170HP, 84 Def&SpDef, 172 Atk/SpAtk, subject to changes in case of low base hp mons. EV training is most preferrably done in multiples of 4(as each stat gains a point from 4 of its EVs)to ensure maximum EV utilization. But, 510/4 isn't a multiple of 4, so, you'll often come up with some difficulties.