Just wanted to point this out as many seems to not realize it.
Normal sends pre 10:
Wyv, Bo, Hermit, Commander, Warriors, Furbolg.
How to prioritize: Hermit > Bo > Wyv > Commander > Furbolg > Warriors > Creeps
Normal sends after 10: Warlocks, Kraken, Ballista (on 12 usually), Demon, Furbolg, Commander, Hermit
How to prioritize: Warlock > Kraken > Demon > Ballista > Commander > Furbolg > Hermit
I've seen so many teams lose to terrible king focus, that it's close to embarassing. Even 1800 elo players who can't focus on king for shit. Focusing your king's attacks is without a doubt the best way of saving heals (except for not leaking in the first place). Sure it's easy to focus on demons instead of krakens and warlocks since they do more dmg. HOWEVER.. Warlocks fucks your kings armor making his hp melt like butter vs a warm knife and Krakens reduce his attackspeed making the wave impossible to kill fast enough.
Hold ALT while searching for creeps to kill, if need be, zoom in on king to make sure you hit the sends you want to kill first. Nothing more important than seeing someone missing on the demon inside a stack of turtles, and knowing that if he had killed the demon, you would have won the game.
Practise makes champs, talk does nothing but make ya look like a cunt!

Peace out!