When the end times come and Google+ begins slaughtering the human race, take pride in the fact that we will be the best-looking corpses!
Those interested in not becoming corpses slain by Google+'s legion of Hunter-Killer drones should being keeping track your friends and people you just don't like that much so that you may use them as bait/distractions/meat shields and buy yourselves some precious time.
Remember, nothing says "friendship" like giving your friends the honor of dying at the hands of an uncaring mechanical monstrosity so that you may buy yourself a few seconds to escape!
I believe I've mentioned it before, but positioning can be everything in a fight. A misstep in lane can cause an unfortunate and unwanted death. One person being out of position in a teamfight can make the fight 4 vs 5 in no time. Learning where to stand to protect yourself can mean the difference between a death and a kill.
Know Thy Enemy
As you jaunt off to lane, you'll probably have an idea of who you're opponent will be. Maybe you have a few ideas. Either way, you should attempt to recall each enemy's abilities to the best of your knowledge. Knowing their passives, abilities, and how each one acts (skill shot, target) will give you a better chance of survival. Let's take Mid as an example.
You run off towards Mid as Leblanc knowing that Lux will be doing the same on the other side. You think back to her abilities and how they operate. Her Q is a snare that is a straight skill shot and will trap two units before it disappears. Her W is an AoE skill shot and her E is a shield that won't harm you. Last but not least, her Ultimate is a straight laser that does a decent chunk of damage. So looking at all these abilities, what's the best way to stay safe in lane? Well, there's a few ways really:
Moving left to right and never staying in one place while you try to last hit or harass will make it easier for you to dodge her skill shots. Maybe not the AoE so easily, but her snare and Ult will become fairly easy to dodge with enough left to right movement.
Since her Q can only snare two units before disappearing, it's not a bad idea to try and stay behind your minions while you try to last hit. If she does throw out a Q and hits two of your minions, it means you have a free chance to harass.
These two tips touch on the most common way to position yourself in lane correctly. While moving, don't forget to keep an eye on enemy creeps' health so that you can continue to last hit. Generally though, you'll want to stay behind a few of your creeps if possible. In laning against Nautilus or Blitzcrank, if you stray to the side where none of your creeps are then you have the possibility of being pulled or grabbed into your doom. With a creep in front, they'll take the hit for you.
Maybe you're at Bot against an Ashe. Her volley, if it hits, can slow you down. However, it can only hit one unit for each arrow, so if you stand behind your creeps then you won't get smacked by an arrow. Once again, it's always a good idea to try and have a few creeps between you and your opponent. Think of them as tiny shield against skill shots. As for targeted spells, you'll just have to keep in mind the range of the spell as there's no real way to dodge them like skill shots.
When the Fights Break Out
Once laning phase ends and group phase begins, positioning still remains very important. Wrong positioning for group phase can turn a 5 vs 5 into a 4 vs 5 or worse real quick. Don't fear though as keeping yourself from death isn't terribly hard. In fact, each role has somewhat of a position to be in during the group phase.
If you're a tank, you'll want to hang out in the front of the pack. You can absorb the most damage and generally have a few abilities that will keep enemies from swarming in. It's your job before a fight to keep everyone safe. During a fight, the objective remains roughly the same with the added job of scaring or catching the enemy carries. Bruiser characters such as Olaf will be more carry killing oriented than tanking for the most part.
Supports will often hang out in the middle of the group before a fight and hang out in the back during one. Their job is to disrupt the enemy and keep their allies alive. Soraka for example can silence the enemy AP Carry to prevent them from pulling off any damage while keeping her own carry alive with heals.
AD/AP Carries should always, ALWAYS remain in the back before and during a fight. Since they all build attack items, their defense and magic resist are lacking quite a bit. If not protected, you'll lose out on plenty of damage and eventually lose the fight. Moving into the middle of a fight when you're so squishy will only mean certain death. On that note, everyone must protect these champs to succeed. They're the most valuable assets on the team. If they're getting harassed by an enemy, then make sure that enemy knows it's not a good idea to touch them.
While I listed where to be before and during a fight, I want to add one more thing. Before a fight can happen, there should always be some sort of initiation. This could be an Amumu Ult, Ashe Ult, or even an Alistar Headbutt -> Pulverize combo. The best time to start a fight is, obviously, when the enemy is out of position. If you see a Leblanc or Graves hanging out in front of their team, then starting the fight will throw it into your favor. Since typing can waste valuable time, try to ping before you jump in. This should be a good enough sign to let everyone know it's time to do some work. Just make sure everyone is relatively close and ready to fight (decent hp, abilites refreshed, etc). Otherwise your ping will be noticed, but no one will be close enough or able to help.
Positioning can be difficult at first, but once you get the hang of it you should notice less and less deaths each game. Knowing the enemies abilities and knowing where to stand are really just half of it. The other half I can't write on as it comes down to experience. The more you play, the more you'll understand matchups and how to make your opponent miss more often. Just remember to move and use those minions for their true purpose as shields. See you all on the Rift.