>>34538912Decide up on a core. NOTE: I'm a VGC guy so this will be geared towards that. The two most common cores are Fire/Grass/Water & Fairy/Dragon/Steel. These cores have offensive & defensive synergy. Think something like Garchomp, Azumarill, and Celesteela. Then you add other Pokemon based around that core, to deal with specific threats, and deal with gimmicks.
You always want your team to be capable of having some way to beat common threats (e.g lando-T) but you also want them to be able to deal with Gimmicks (evo boost baton pass eevee), last it needs to have a good form of speed control.
So lets say you go with Garchomp, Azumarill, Celesteela (I'm not even sure if that's actually a good core but just roll with it). You decide that something like Marowak with it's Lightning Rod will be helpful in protecting Azumarill and Celesteela from Tapu Koko and it resists Tapu Koko's fairy STAB too. You then decide to pick up Cresselia due to it's ability to deal with Lando-T with Icy Wind/Ice Beam and it's excellent Speed Control it has with Icy Wind & Trick Room. Then you decide that Prankster Sableye will be a good choice since it can taunt enemies to prevent gimmicks like baton pass and can also provide fake out support. Only thing that team would be lacking is a Intimidate Pokemon which is pretty important in VGC so maybe Scrafty instead. (I'm not sure if that team would actually be good, just naming whatever comes to mind first).
Basically, just start with a core you want a build around it.
