I tend to start of with dagger for some small amount of attack speed, and go mid.
Play passive and occasionally try and get a blinding dart on your opponent, and shoot at him/her while they run away. keep doing this until you get you ulti and start to place 2 mushrooms on each corner of the river entrances and one in the middle of either bush.
Hoping that your target wants to kill you as you are reasonably squishy and try bait him/her into the mushrooms.
Go back to base after you have killed or injured you opponent and have time to get to base and back. get malady and head back by now you should be doing 1.3 - 1.5 attack speed. start farming with your poison dart and placing mushrooms in the middle and possible get away points.
after some time you should have the money to get mobility boots and use your speed to your advantage, ( hit and run) pretty soon you should be involved in team fights and this is when you want to get sword of the Occult make sure you get either the last hits in or assists, even one shot will do to get those stacks on the sword.
Carry on like this for some time finish the build and you should be doing some sever damage in team fights and able to escape.