Feel free to post some cool tricks such as fog abuse, orb walk, unexpected moves and so.
I will start with orb walk, the expression is used for stoping orb animations on heroes who have orbs as attacks (like bone , viper, silencer, obsidian etc ) . The points is that heros like those after attacking need some time to do next attack because of animation of orb. Ofcourse that will slow you much in chasing and let your opponents flee. Also to do "orb walk" you need to single cast your orbs (not on autocast), on istance with silencer "w" and left click on your target. Next images will explain how to do it. Silencer is used as instance:
Have in mind that you can orb even if you hero doesn't have an orb effect spell, as mentioned for example you are chasing a hero with potm, hit an strike and move towards your target, this way you won't allow your enemy to get far from you as you are abusing high move speed of your hero.
One more tip is to use "A" or "attack button" on ground near target instead of right clicking enemy hero while near creeps, this way you won't draw agro upon yourself which will cause nearby creeps not to attack you while your enemy might drag your creeps on him making you have a big advantage in dps.