Tinker

Boush the Tinker is a ranged intelligence Hero who relies heavily on his assortment of nukes for ganking and pushing. He is able to reset the cooldown on his abilities, which in conjunction with Boots of Travel gives Tinker global mobility rivaled only by Nature's Prophet, making him a constant threat. His abilities' mana costs are very high, so he must constantly use his ultimate, Rearm, and Boots of Travel to go back to base to heal. Tinker must acquire Boots of Travel, they are not optional; and if he acquires them early with a level advantage he will make short work of the enemy. Tinker is also the only hero in the game with two abilities that can be upgraded with an Aghanim's Scepter.

Tips
Note 1: Though this is an effective farming method, it can also hinder the overall success of the team by stealing potential safe farming situations from heroes that need it more than Tinker. Consider the lane you are looking to teleport into, where it is in the lane (i.e., is it close to your or your enemy's tier 1/2 tower?), if there is a teammate already heading to that lane or in it already, if it is close to the top of the minute. As a rule of thumb, if the lane is close to your tier 1 tower and there is still a tower in a safe lane, let your carry take the farm. If the lane is pushed to a tier 2 tower, you should let your carry take the farm unless they will not get there in time to capitalize on it in either case. Consider if the location is safe for you to TP into or if there is a teammate close to it or already farming it. It is rude and counter productive to actively steal farm from your teammates. If it is close to the top of the even minute Odd:35-odd:45 where odd is an odd number, consider TPing to a creep or tower with the most direct path to your ancients to stack them. This can create a sizable amount of experience and gold within your team.
 * Laser is an extremely powerful nuke that ignores magic resistance. Use it as primary source of damage for the Tinker.
 * If there is only one opponent on your lane, you should max out laser first, as it deals high damage per mana cost compared to heat seeking missle. The blind effect should never be underestimated as it acts as a pseudo-disable on hero physical attacks.
 * Heat Seeking Missile has a really long range. With rearm, you can spam a barrage of heat seeking missiles as to harass enemy heroes.
 * March of the Machines is a perfect farming tool. It's a bit tricky to aim though. You can overlap several March of the Machines using Rearm to deal massive area of effect damage.
 * Bottle is a somewhat required item on Tinker, even if you don't midlane, as it decreases the time you're in base and increases the time you can stay out of base.
 * You can stack commands by holding shift to prevent unintentional Rearm interruptions. The Tinker will perform stacked commands right after finishing Rearm.
 * Boots of Travel is a required item on Tinker. Used in conjunction with Rearm, it allows you to teleport around the map quickly.
 * ***DO NOT DO THIS INDISCRIMINATELY (see Note 1)*** Once the Tinker gets Boots of Travel and Soul Ring, start teleporting back and forth between lanes and fountain to farm everything on the map.
 * After BoTs, Soul Ring, and Bottle, Tinker should get either a Blink Dagger or Force Staff or both. Blink Dagger is much better for mobility and safety. Blinking immediately after teleporting should prevent any attempted ganks, and March has enough range to farm a wave even if you blink into trees. Force Staff provides 10 intelligence, but not nearly as strong of a repositioning tool.
 * It's not always best to level up Rearm at levels 6, 11, and 16. At level 6, if you don't have Boots of Travel or a Soul Ring, you won't have the mana to sustain Rearm. It's usually best to pick up your ult once you've gotten BoTs or can clear out stacked ancients with March + Soul Ring + Rearm. This is usually a good way to get the last 1000 gold to get BoTs and get a level or two. For levels 2 and 3 of Rearm, consider how large your mana pool is before adding the point.
 * Participate in ganks whenever you get a chance. "Missile, Laser, Rearm combo" should be enough to finish off any fleeing enemy early-mid game.
 * Always kill enemy silencers and disablers first because they can ruin your spell combos.
 * The Tinker can permanently disable and kill enemy carries in the late game phase. Simply repeat "Scythe of Vyse, Missile, Laser, Rearm" cycle till your target is dead. Make sure you have sufficient mana pool and you're performing everything quick enough.
 * Another popular item to get as the Tinker is the Dagon as it works well with Rearm to deal massive burst damage provided a sufficient mana pool is present. The combo of Dagon > Rearm > Dagon is deadly when paired with Heat Seeking Missile and Laser.
 * Ethereal Blade is also a very useful pick-up on Tinker. Although it counts more as a luxury than anything else, it will amplify the effects of Dagon (but not laser, since it's pure damage, and not missile, since it does not target ethereal units) by 40%, making it do 1120 damage (when fully upgraded). Few heroes in the game can withstand a combo of missile, ethereal, laser, dagon, rearm and repeat. Note: for the missile to hit, it needs to be shot before the enemy is ethereal. This is usually done by firing the missile from long range then blinking in to e-blade/dagon/laser. Timed properly the (fully upgraded with 125 int, after 25% magic reduction, combo) does 1842.5 damage.
 * Be careful when you use your spell combos as the Tinker is extremely mana-hungry. A few lasers and you will quickly find yourself without mana if you're saving up for Boots of Travel or Scythe of Vyse.
 * When facing auto attack-heavy heroes such as Lone Druid and Ursa, it may be wise to build Heaven's Halberd. In conjunction with laser, you effectively can disable auto attackers up to 6 seconds for melee heroes and 7 seconds for ranged heroes. Adding Scythe of Vyse up on this brings a disable of 9.5-10.5 seconds. Using Rearm properly allows you to completely shut down certain heroes.
 * When the Tinker acquires Boots of Travel and has enough mana to rearm and withdraw, he is able to confuse opponents because his pushing ability forces the opponent to defend their towers and he's just able to "Lane-Fountain-Lane", again and again.

Trivia

 * The Tinker's voice actor, Harry "Hal" Robins, also voiced Dr. Isaac Kleiner in Half-Life 2. Many of Tinker's voice lines reference characters and events from the Half-Life universe. In addition, the name "Violet Plateau" is quite similar to "Black Mesa," and the events described in Tinker's backstory are remarkably similar to the events of Half-Life.
 * The Tinker's alternate/fun name in DotA was "X!!", name of a professional DotA player.
 * Tinker's line "I tink! Therefore I am!" is a reference to the philosophical statement "I think, therefore I am." proposed by René Descartes. Its original Latin words are "Cogito ergo sum."
 * Tinker's line "Tinker, failure…Soldier…Fie…" is a reference to the 1974 spy novel Tinker, Tailor, Soldier, Spy by British author John le Carré about George Smiley (who was played by Gary Oldman in the 2011 film adaptation).