Do you tend to have a set formula for a successful team? Do you stick to one type, or set out to have specific Pokemon by the time you face the Elite Four? Does your team tend to stay the same from game to game or do you enter new gen Pokemon into the mix? For me, I always played with all the Eevee evolutions, with the exception of Sylveon and Glaceon.
I usually use the local region's Pokemon when I play to finish the game first. It's a good way to see if there's new Pokemon you will come to like as you use them. However, for all of my endgame play though, I always just mostly base on how the Pokemon looks like. Heck my main party that I use for combat is composed of cuties! I believe that each Pokemon, the ones that have evolved to it's maximum at least, have a way to handle itself in battle, despite losing out in terms of stats against other Pokemon, so I invested on this and made my team of 5-6 perfect IVs. I can be proud to say that I use my favorites based on how I like them, not on how strong they are. Truly enough, I'm quite satisfied in the online Battle Arena, but that's not part of the topic. So that's it: I choose Pokemon on how I like them, especially if they're cute, hahaha! I will just formulate a tactic in order to maximize teamwork. My team is composed of Bellossom (my favorite), Vivillon, Cherrim, Cinccino, Emolga, and Sylveon.
It really just comes down on who is the strongest Pokemon, as well as having a variety of Pokemon types. You will have a difficult time with all water Pokemon, or whatever. My teams always vary because the only Pokemon that is confirmed in my team is my starter.
I like variety in my teams but it usually goes one fire, one psychic, one flying pokemon and the rest I just mix and match depending on whatever else I catch. I usually keep the really rare pokemons on the top of my team and those I collect I give them weird names that sound really scientific so I would feel like a scientist discovering a new species. LOL
I kind of pick my team at random; which Pokemon I come across along my journey in the game I'm playing that I feel a connection with, that's what I go for. This team may not be the best in terms of competitive battling, but these are the ones I use most often: Umbreon, synchronize ability, Dark Pulse, Psychic, Sucker Punch, Swift Gengar (shiny/mega), levitate ability, Shadow Ball, Toxic, Nightmare, Thunder Dunsparce, run away ability, Yawn, Blizzard, Flamethrower, Dream Eater Weavile, pickpocket ability, Ice Beam, Shadow Claw, Icicle Crash, Focus Punch Braixen, magician ability, Fire Blast, Magic Room, Flamethrower, Overheat Furfrou (shiny), fur coat ability, Surf, Wild Charge, Grass Knot, Dark Pulse
I tend to just choose my team as I play. I don't plan it at all; if I like a Pokemon, I keep it. I usually try to make sure I have a range of types, just in case, but if I really like a Pokemon, nothing's going to stop me from using it! As for the Elite Four, I just train my Pokemon a lot and hope for the best. It doesn't stay the same from game to game, as I usually like to play with the region's Pokemon only.
I try to cover as many bases as I can, though it depends on the game. Because I know LeafGreen and FireRed so well, for example, I know I need a water-type in my party, both for surfing and so I can more easily tackle Lance of the Elite Four with Ice Beam, which tends to pair well with water-types. By the same token I know that the Elite Four of those games pretty thoroughly resist poison-type pokemon, so you won't often see a Muk or a Weezing on my team. It's not necessarily the most fun way to play, but I always have the Elite Four in my head so I can't really help myself. If I don't know the game so well I'm more inclined to pick pokemon I just plain like, though if I find that a pokemon's not very good in battle I'll probably get rid of it, regardless of a cool design. I do usually like to have one underdog on my party, though. They can't all be uber-powerful combatants.
