Creep control techniques

Last-hitting
Last-hitting is a technique where you (or a creep under your control) get the 'last hit' on a neutral creep, enemy lane creep, or enemy Hero. This is the only way to get gold from creeps apart from Hand of Midas, Devour, Death Pact, or Demonic Conversion, and gives much more gold than otherwise when done to towers or Heroes.

Creeps are your 'safest' bet on using last hits to gain a good chunk of gold. This is the primary source of gold in Dota 2. It is always desirable to get a last hit on a creep, although when laning with a carry as a support do not take any last hits, instead, let the carry get them. Supports should focus on harassing enemy Heroes and denying your own creeps.

Auto-attacking refers to the usually less desirable technique of simply letting your Hero attack at will. Because this decreases your chances of getting last hits, especially if your damage per second is low, and it pushes the lane forward, this is not beneficial. In the late game, however, Heroes often do enough damage per second to simply auto-attack and last hit. Auto-attacking can be useful in any case if you wish to push a lane forward, since it kills enemy creeps faster. This is especially useful for killing towers. In the early game, however, pushing towards an enemy tower is considered dangerous, as it leaves you far from your own towers and makes it much easier for enemies to gank you.

Heroes also give gold when you kill them. Everyone who did damage to an enemy Hero within 15 seconds of their death gets an assist. If you were the Hero who delivered the last hit you will get the kill and the bonus gold for it. If your tower or one of your team's creeps gets the last hit on an enemy Hero, the gold is split between all Heroes who got an assist. If only one Hero hit the enemy before your tower or creep killed them, that Hero gets the credit (and the gold) for the kill. If no allied Heroes assisted in the kill, the gold is split evenly among all five Heroes on your team.

Towers give a global bonus of gold when razed, but they also give a hefty amount of bonus gold to any hero who manages to get the last hit on one.

Denying Units
Allied creeps and siege units can be denied once they fall below 50%. To deny a unit, you must force an attack command on it. (By default this requires you to press 'A' and Left-click on the unit.)

Denying creeps is an excellent way to control a lane and gain a lead over your opponent. It not only prevents them from gaining gold and moves the lane towards your tower, it also denies your opponent experience which can cause a noticeable level difference in lane.
 * A denied creep divides 36 exp to enemy heroes within 1300 range. A melee\ranged creep would normally give 62\41 exp in 1300 range respectively.

Some units such as Warlock's Golem and Lone Druid's Spirit Bear grant a significant gold reward should an enemy hero successfully destroy them. Denying these units is an excellent way to prevent giving the enemy free gold when the unit is unlikely to survive.

It should be noted that the Necronomicon Warrior will not trigger Last Will on a deny, though this is still a waste of the warrior's utility and is not recommended.

Denying Towers
Towers may only be denied once they drop below 10% health, and doing so will significantly reduce the global gold reward the enemy team gains from the tower's destruction. The difference between the standard tower bounty and a denied tower's bounty is as follows: Denying a tower will also prevent an enemy player from receiving the 150-250 bonus gold for the last-hit.

Denying Heroes
Heroes can also be denied under specific circumstances. A denied Hero will prevent the enemy from gaining any experience or gold from the kill, but will still lose gold upon death.

Most Heroes or other controlled units can only deny an allied Hero by attacking him when he is under the effects of certain spells and under 25% health. The 3 ability effects that currently allow a Hero be denied in this way are:
 * Doom's Doom
 * Queen of Pain's Shadow Strike
 * Venomancer's Venomous Gale

During Supernova, Phoenix may be denied in a similar fashion, though the sun must drop below 50% health.

Always consider these options, but be careful as you don't want to deny a teammate that would have otherwise survived.

It is also possible to deny yourself granted that you have access to at least one of the following items.
 * Bloodstone's active, Pocket Suicide, will immediately kill the wielder. This is treated as a suicide and allows the item holder to deny themselves at will.
 * Helm of the Dominator's active, Dominate, if used on an enemy ranged unit that is attacking you, can also result in a suicide or deny. This occurs if the unit has a projectile attack in flight, becomes dominated, and then scores the finishing blow with the attack it already made. Example: http://www.gfycat.com/BelovedBowedAndeancat

There are also some hero abilites that deal lethal self-damage and, as such, can be used to commit suicide. These Heroes/Abilities are:
 * Techies' Suicide squad, Attack!
 * Pudge's Rot
 * Alchemist's Unstable Concoction
 * Abaddon's Mist Coil
 * Bane's Nightmare
 * Bloodseeker's Bloodrage

Bane's 'Nightmare' and Bloodseeker's 'Bloodrage' can also be cast on allies, which allows these two heroes to deny teammates as well as themselves.

Lastly, you may deny yourself by running into a neutral camp (or Roshan's pit) at low health, and letting them kill you. This will prevent enemy heroes from getting experience and gold from killing you.

Attack animations and missile speeds
Shorter attack animations (on all Heroes) and faster missile speeds (on ranged Heroes) make last-hitting easier.

Equilibrium
It is important not to push your lane too much, but try to keep the lane creeps fighting in approximately the middle of the lane so you never are too far from the safety of your tower. Creep equilibrium is generally maintained by balancing last-hitting and denying, and on occasions attacking your own creeps before the deny point or attacking the enemy creeps to push. This technique is also known as static farming. Creep pulling can also help maintain equilibrium.

This is always situational though being pushed might be a bit safer but if the enemy lane is able to slowly chip away at your tower you should push harder. Also access to the side shops might be hinderance on occasions.

Creep Blocking
Creep Blocking is a tactic that makes the equilibrium of the lane lean towards your side. This is accomplished by physically blocking your creeps' path with your hero so they take longer to reach the middle of the lane. Since your creeps move more slowly, they will meet closer to your tower, making it safer for you to farm, and more risky for the enemy.

Pushing
Pushing is the act of damaging enemy creeps through auto-attacks or through abilities. Pushing is used to move the creepwave towards the enemy tower, or simply away from the allied towers. Late-game, pushing is used to move creepwaves towards the enemy base to win the game.

Some heroes have abilities that facilitate expedient pushing, such as Leshrac's Diabolic Edict, or Pugna's Nether Blast, which can damage multiple creeps and towers at the same time.

Roles and last-hitting
Depending on your role in your team you should focus on different things.

Carries should focus most of their attention on getting last hits.

Supports should focus on denying creeps and harassing enemy Heroes so that their carries can last hit without being harassed. Do not throw away the last hitting entirely as a support, because there are some last hits which are impossible for a carry to get (for example, the creep is being killed faster than a carry could possibly get in the attack range).

Supports can also creep stack to help their carry farm.