The easiest starting point to build a quality team

I probably will not be continuing this topic all by myself, so if anyone wants to fill in other stepping points and what you could do start-to-finish, feel free. Intel is welcome no matter what.

Trying to start off in the Pokémon metagame without full social awareness or understanding of a team, as a rookie, can be a living hell. And even then, after the research done in what's in each tier can be a massive chore.
Here's a few quick ideas to help you get your foot in the door w/o you getting rekt more often than David Carr was, when he played behind the Houston offensive line at the time.

First off, ask yourself: 'What do I feel more comphy playing with as far as RPGs are concerned? Bulk? Speed? Status? Or a mix of a couple ideas?' That should help lead you before you scout out the gamers in the tier you are playing and the Pokémon's sets (especially if you intend to use a wierd set such as a ResTalking togetic with Psycho Shift).

The next thing you need to do is look at the Pokémon and your playstyle, then think of either A: think of your defensive core - which tend to be 2 Pokémon with a third to support with either being a straight attacker or a 'pivot' switch; or an offensive core. Granted, you need to think about the weaknesses and resistance so you can add Pokémon to build off of it.
A prime, nasty defensive core in gen 6 overused for example would be mega venusaur/heatran, with landorus-therien as your bulky pivot that can hit hard.
Offensive core I am not as good with unless I have a theme bult around them. The biggest example is sticky web in general.
A Side note you need to keep aware too is how you spread your EVs. Mistraining your Pokémon will cost you more games than you think.

Thirdly, learn how the metagame is shaping up and adjust your team to better deal with the game itself. You don't wanna get caught off guard cause you came into a match unprepared and suddenly, because you went to defog all your opponents' hazards, only for SURPRISE! Bisharp is now at +2 cause Defiant triggered off the evasion decrease, then rekt by a +2 knock off of all your items. Even worse there if he's behind a substitute.

Finally, try to learn how your opponent will play, and plan out ahead. Mind games are about 30% or so of the game itself, so forcing bad plays on s/he can be the difference; especially if you got the team disadvantage.

If anyone has other tips or ideas, feel free to post.

 

I derped when I typed about the defogging thingie and when I phrased 'mind games', so thanks for clarifying what I meant to explain.

By the way, when I used Bisharp as an example, I was shooting a nasty prediction idea you did not want to be caught in (if the prediction screws you and Bisharp comes in on your Defog) because of that potential +2 Sucker Punch, or if Bisharp is faster it can substitute up with Defiant activated from said switch. The exception is Latios/Latias since they normally pack something that will end Bisharp's potential wallbreaking/sweeping dreams.
You're very right about the 'win condition' by the way, however, my experience would lean to the other way. My big problem with building a team focusing on one Pokémon is, if you're not careful, you can potentially screw yourself against one playstyle or theme (again, based on my personal experience).
Also, thank for generalizing the term 'core' from where I focused on. You did me a huge favor there.
Hey, at the bare least it's a start for someone that has problems explaining stuff.

Edit: Skarm/Bliss was a popular Gen 4 set too. However, with Eviolite around, Chansey gave it stiff competition to fill that role. Again, like you said, it got kinda hurt by Knock Off boosted to base 65 attack.
I mainly mentioned this gen with Venusaur/Heatran cause of how both of them synergize and potentially, can make a nasty water/grass/fire core with a third Pokémon. Venusaur has Thick Fat on mega, strong overall defenses, can force sleep fodder, use synthesis or leech seed, and/or be a straight out tank. Heatran though doesn't get a self-healing move, however, but its movepool (for multiple roles, moreso hazard shuffling), stat pool, and typing can (provided venusaur is physically defensive) wall out what venusaur cannot (case and point Talonflame).