Guide to a few general skills/tactics

Last hitting:

In league of legends a large amount of your money comes from killing creeps. Instead of focusing on kills you might not get or get yourself killed in the process. During laning it is usually a lot smarter to focus on killing as many minions as possible.

When lasthitting. Try not to auto attack minions. By doing so your lane will be pushed forcing you to fight closer to the enemy turret and be open to jungle ganks.
Instead, wait for the minions to damage eachother until you feel you can kill a minion with a single auto attack. This way you get the gold and the minion wave stays in place.
It is also usefull to know the auto-attack of your champion. Some champions deal more damage, some attack slower and some have a long animation before the actual damage.




Zoning:

Zoning gives you lane control and keeps your enemy from farming. Not much more to be said except this tutorial.




Focus:

During teamfights, what usually happens is there are more than one good target to take out. Resulting in a chaotic teamfight with no kills (for your team) and usually a death if the enemy team has a better focus.



Usually tanks position themselves in a way to draw focus fire. This however is something you should avoid. Do as much auto-attack damage to them while not burning your major spells. Keep them away with crowd-control and try to reach their damage output without getting your team killed.

A tip connected to focus is to never chase impossible targets. If a target gets away and it will take you way too much time to take it out. Let it run, instead help your team focus down new targets. By chasing you get your all-important ad-carry or ap-carry killed because they need the protection of the solo-top and jungler who usually are more sustained damage and crowd-control.


Gearing:

Many people use guides on sites like mobafire and lol-pro. This a good way to get a general idea of the champion and what you should look like on endgame. However it is very important to know what items are out there. If on solo top you have to lane against a AP carry it might be a good idea to get a "negatron cloak" so you wont be hurt a much.

Don't be stuck with buying exactly what the guide tells you to buy. Instead have a good feel for what you need. If you play against a AD heavy team as a tank, torn-mail might be a good idea. If you are Rammus and they have 2 Ap-carries rushing armor is not the way to go. Get yourself a force of nature or another anti-magic item.

Counterpicking (draft mode):

During draft mode first 6 champions will be banned. After that you or your enemy will pick the first champion. This is crucial because they can pick a strong champion that has been left open. If this champion will be a problem the trick is to counter-pick it.

For example if your enemy picks Nasus as solo top. A good way to counter him is picking Teemo or Fiora. These two champions have the ability to avoid being hit by Nasus' Q and therefore Nasus can't do a lot of damage.

Another thing to remember with draft mode is the fact that you can trade with teammates. The first pick is strong but also weak. The previous example showed how easily you can get countered and in the process ruin a lane. It is hard to pick a champion to wont be hurt too much from being countered. Smart choices to first-pick are a solid jungler or support. A jungler like Lee Sin will not be countered easily and usually countering a support is not worth it.

Things to consider before first-picking are a mid, top and Ad-carry. If your solo top gets countered you will lose that lane, if your mage gets countered you will lose that lane aswel and even worse, mid tower. If your Ad-carry gets countered your main damage output will get a hard time farming and your damage will suffer for it.


Warding:

A general rule in League of Legends is: "Buy a ward, save a life". Wards are 75gold each or 125gold to reveal stealth (Mobs, shrooms, wards etc). If you are going for your own vision the green ward of 75gold will do the trick.

Placing wards in the most dangerous ganking routes will save your from harm more than once. Knowing where to place it:



These are the most useful places for wards. Placing them there will let you see junglers coming in time or other champs leaving their lane to gank.

The support and jungler are the main champions responsible for warding the map. However if you are solo top or mid don't be cheap and get yourself a ward with some spare gold. Getting killed is much more expensive (Giving the enemy team free gold).

Don't forget your enemy will do the same. If you are going for a jungle invasion or a gank. Assume you have been seen. This prevents you from being surprised their jungler shows up. Try knowing where their wards will be and removing them with Oracle or a pink ward. By doing so you reduce their vision of the map and force them to play more safely. Leaving them open for ganks like this will not ensure kills against good players, it will make them hang back and reduce their farm.


Timing of jungle mobs:

The role of a jungler is not only to take out the mobs in the jungle and place ganks if possible. By carrying wards you can protect yourself and your team by warding jungle entrances, important mobs like blue buff, dragon and baron. However it's also of importance to time the most important mobs.

Dragon has a 6 minute timer and baron 7 minutes.

The way this is done is by saying what time the mob will respawn. For example when you kill dragon at 22:00 you type in chat: "Dragon at 28:00". This way your team can be ready at the right time when it respawns.


(More follows, share some general tactics you think belong here)

Updated. More coming.

Let me know if you miss something.