GG vacation

do not use stun for last hit i repeat do not use stun for last hit.
terror wave can be used to know opponent's position/also to check if enemy's doing roshan.

madness/lothar's edge/dagon, which suits you better. i only use dagon for last hit, but when i don't need to, i buy butterfly.

courier/flying courier and bottle. very useful since you're a stunner. but know when to take the powerup. someone else might need it. but don't buy bottle first. it's courier and tango+mana something.

swap can be used as offense and defense. like when you're chased, by say, raigor. his stun is aoe and you can avoid that by swapping someone behind raigor. also if they clicked someplace past you, you'll have a few seconds to run opposite them. adds to survival.
in offense, swap someone that needs to die first. and if the one you swapped will die fast, don't stun that anymore, stun someone near you (preferably the one that can immobilize you) for you will be their target.

many also fancy desolator since,but since it's an orb effect, it's either desolator or lifesteal(mask of madness/helm of the dominator).