I've been a forum member since before it was cool. I just mainly lurk like the creepy dude at a club with his hands in his pocket.
HOWEVER, I figured I'd contribute to this forum by giving my experience in competitive gaming. Love it or hate it, I've got some interesting history on the topic.
First thing to know is, being a good gamer doesn't actually mean that you've just played a game enough to rock at it. Competitive gamers don't understand ONE game. Rather, they understand competitive play. My area of expertise is World of Warcraft; I held an arena rating of 2200 in the days of Burning Crusade. In WotLK I held 1800. In League of Legends I've hit elo of up to 1600 (though right now it sucks). In Starcraft II I had a brief stint in Diamond before quitting.
My credentials aren't too impressive. However, I learned some awesome lessons in World of Warcraft. I met up with a player named Noone. Anyone around in the days of TBC will know him as hands down the BEST Frost Mage in the game. You can still check out his video here:
He was a part of DoomSquad which was a huge PvP clan for WoW which had the best players, including people who rose to huge e-fame in WotLK and whatever they're on now. Cataclysm. That one.
Skill in a game is constructed of three basic parts:
2. Learning from LOSSES, not wins
I never had ambition to be a pro gamer, but I played with some of the top of the World of Warcraft chain. I realize these boasting rights mean nothing in life. But screw you, I can beat you in an MMORPG I quit playing, so who wins that battle?
Okay, advice from Noone:
SPOTTING WHAT YOU DID WRONG:
When you're playing games to win, leave your ego at the door. Your losses teach you more than your wins. When you win, you did something right. When you lost, you did something wrong. This applies to team games as well. You'll never get good at League of Legends by blaming your team, in the same way that you'll never get good at World of Warcraft by blaming the person you're in arena with. I learned this when I started playing Noone in Starcraft II. I was gold league with 100 wins or so. It was his first game. I won, of course. It was a cakewalk. But in four games, Noone had watched every replay and beat me hands down, to the point where I couldn't touch him anymore.
SOME ASPECTS OF A GAME MIGHT BE FUN, BUT THEY DON'T MAKE YOU GOOD:
World of Warcraft has raids; League of Legends has attack damage characters (and people want to play this all the damn time); Call of Duty has a campaign and side-games. These things are fun. But they don't make you a better player. Auto-locking your character in in League of Legends is retarded. You won't learn how to play the game well if you're hell bent on going solo and ignoring your team. Playing AD Carry every game isn't helpful, it's annoying.
There is always more to learn. The better you can play every character in a game, the better you are at beating them when you're playing someone else.
NOTHING IS OVERPOWERED:
Okay, sometimes things are overpowered. But bitching about them doesn't help. If you fulfill your role correctly, you'll win. I know this feeling so well. Video games have a "noob" race. In Starcraft I thought it was Protoss, in World of Warcraft it was Death Knights and Paladins, in League of Legends it's someone who I fed.
The hard thing to realize is that when you're losing, YOU'RE losing. It's not their character. It's you, and your team, and blaming your team doesn't teach you anything.
Most games, you're playing as a team. LoL, WoW, CoD. You need to learn how to compliment your team mate's abilities. This is a huge mistake people make: getting greedy and stealing kills. This especially applies to League of Legends. Yes, you may have earned the kill, but a 27/2/0 Katarina (for the clueless, 27 kills, 2 deaths, 0 assists) might be very strong, but nowhere near as strong as a team where everyone has 6 kills.
The fact of the matter is, the more you play, the better you will be. Grand Master's League for SC2 is dominated by people who play all day, every day, and the only reason I got my WoW rating to 2200 in TBC is because I did NOTHING else. This is a true factor, but that's not to say that you shouldn't be winning 60-70% of your games. The difference is, you move up ladders faster and learn more if you're playing more.
Games have mechanics that are important to learn. A basic understanding of these will greatly improve your skill. In Starcraft II your mechanics are economy and advantages; push on economy, push on advantages.
In League of Legends you have team composition and decision making; compile your team correctly, and don't get greedy with your decisions. When you have an advantage (i.e. one person has been picked off, making it a 4v5) use the opportunity to PUSH for a win.
In World of Warcraft, you have individual character mechanics; don't sit in melee range of a warrior, don't let the enemy team use crowd control (cc) on you until your DPS dies.
In Call of Duty you have advantages and positioning; Get the right position, take out an enemy and push your advantage a man stronger. Same thing with Quake. Dominate the position the enemy has to take to get weapons and upgrades, win the game.
I hope this helps. A basic understanding of competitive play will work for every game. If you understand these rules and start WATCHING your losses, you'll be destroying me on gaming ladders soon.