A word of advice: have fun.
So, as of right now, I have 2 years of playing this game under my belt. For the most part, I have played in the lower ELOs, as well as the lower ranks (Bronze mostly). I used to get frustrated, angry even, at the game, at me, at my teammates, at the opposing players. I would get so upset, it'd ruin my night, and I would be easily agitated at my friends. Then, I had an epiphany: it's just a game. We are all just players playing a game. Finally, I could play a game without getting angry at my teammates, the people I know as friends, both in the virtual and real world. We have inane goals now, having all five players starting in one lane to mess with that laner. We would make the enemy team chase an individual throughout their jungle, and see who could go the longest (we timed it). It stopped being this "win or nothing" mentality, and for the first time, I am laughing from start to finish. More than that, I started to improve. At the beginning of Season 4, I placed in Bronze V immediately. Then, right before URF came out, I started having fun with it. Since, I have climbed a whole level to Silver V. I will never say I am great because of it, but I am now much, much better than I used to be. I finally realized why: because I am not stressed out, because I am not raging at bad teammates, because I am taking a second, looking back at myself and saying, "Oh, I probably ought to buy a ward, since I have the money and space for it," among other things. The next time you go to play a game of League, take a second to get together a group of friends, and say, "Hey, you wanna play a game where we goof off?" Make some inane goal, like playing as Dunk Squad, or all starting top to go after Sata... er, Teemo. Enjoy yourself. Maybe you can't get all 5 friends on at once. Go play a solo queue, and make it a point to be positive, no matter what happens. Take a second to realize you make mistakes, and laugh at them with your teammates (say, "Did you see that epic facecheck I just pulled off? By the way, their team is right here." <Pings over dead body>) Don't purposely make mistakes, but when you do make one, laugh about it. Laughing will allow your mind to register the mistake, and you can then make changes in your gameplay to fix it. And remember, we all are here to have fun: don't deny yourself that pleasure just because things aren't going your way.
<P.S.: Rito, please move the surrender time limit to 35. 20 minutes is waaaaayyyyyyy to early to nail the coffin. The most informative part of any game is how a player reacts to adversity, and when you allow them to just give up on games so early, you take away this teaching period. Who knows, maybe the enemy team makes a crucial flaw, and you turn the game on a dime by playing smarter. I have seen massive gold differences melt in a matter of 5 minutes, and I am not so special that it will only happen to me.