Only pick this up when there's an enemy Jungler. Try not to place this so it blocks the hard camp, use Shadow Walk to block easy camp by 0:30. Place ward to monitor the jungler's HP, get in for the kill when it's HP is low enough.You can place this to block the pull camp.
Pick this up if you're going for farms and you're laning with a non-solo hero.
Like a cutting a butter with a hot knife. Once you get this, aim for Low Armor enemy like Alchemist before or after he uses Chemical Rage for easy 1~3 hit kill.
Put this on enemy auto-attack carry.
Rush this first instead of Heaven's Halberd if you're having a hard time with enemy casters.
Anti - Escape and Caster. Use this when you're solo-ganking Nature's Prophet in his solo pushes.
also use this on Brewmaster before he uses his ultimate or other enemy heroes with natural escape ability.(Blink, Leap, Hook, Roll)
Get this after last because up until this because the enemy are getting harder to kill.