Start with Boots 1, HTOG, and 3 Health Pots.
Lane left or right. Use HTOG to get green or blue buff before minions meet. Then, meet up in the lane and sustain. Gank when possible.
Then go back and get Heartseeker and use Creeping Curse as a replacement for frostbound hammer. Heavenly agility will also help later when it comes to chasing down enemies or escaping. Remember, your leap is also a slow.
Point of this build is that you have high damage, fast speed, and your abilities will have a ton of firepower.
Instead of getting souleater or executioner, you can get witchstone if their team has primarily ad carries.