Tinker

Tinker is a ranged Hero who relies heavily on his assortment of nukes for ganking and pushing. He is able to reset the cooldown on his abilities, and in conjunction with Boots of Travel he can push the lanes on par to other pushing Heroes such as Nature's Prophet, as well as permanently shutting down enemy carries. His abilities' mana costs are very high, so his ultimate, Rearm, and Boots of Travel serve a long way towards going back to the base fountain to restore his mana.

Tinker needs to farm his Boots of Travel fast for his ganking and pushing potential to really rise. If he farms it too late, he might not be able to cope up with it. He is recommended for intermediate players.

Tips

 * Laser is an extremely powerful nuke that ignores magic resistance. Use it as primary source of damage for the Tinker. Linken's Sphere blocks the blinding side effect but the target still takes damage.
 * Heat Seeking Missile has a really long range. You can spam it from a safe distance 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.
 * The Tinker is arguably the best solo mid hero. He can constantly harass his lane opponent with Laser and Heat Seeking Missile forcing him to stay away from creeps. And if he gets pressured by roaming heroes he can always farm safely using his March of the Machines from afar.
 * If you do solo mid as the Tinker, a bottle is a wholly worthwhile item. Not only will bottling runes benefit you in your ganks, but once you do get your Boots of Travel, you will be back at the Fountain more often than most, making bottle refilling easy even if you can't find a rune.
 * 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 commonly built item on Tinker. Used in conjunction with Rearm, it allows you to teleport around the map quickly.
 * 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.
 * Participate in ganks whenever you get a chance. "Missile, Laser, Rearm, Missile 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. 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.
 * A Force Staff is another useful item for the Tinker. It's cheap, provides Intelligence, and has an active ability that, in conjunction with Rearm, can get you out of sticky situations in a heartbeat. A Blink Dagger can be used for a similar purpose, but because it does not provide additional stats, it is usually preferable to buy the Staff instead.
 * 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.
 * 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.

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.