My experience with running RP groups is to keep everything IC as much as possible. Roleplaying doesn't always mean speaking in long winded terms of phrase. If you are in a combat situation, you do not break out your prose and speak eloquently about the situation. You speak in short phrases, sometime laden with profanity.
As long as you keep the topics of conversation about the task at hand while avoiding breaking the 4th wall, you are staying in character.  If some directions cannot be translated into IC without lots of writing, I use OOC brackets within a message.
Example:
"When you see its health get to 5%, burst DPS it down ASAP!"
"When you see it's near death ((5%)) hit it with everythin ya got!"
_____________________________________________________
You can even make more silly emotes to explain things like AFKs.
"brb afk 5min"
vs
emote: "*suddenly falls asleep standing up ((afk 5 min))"
"brb smoke break. be back in 5"
vs
"*takes out his pipe from his robe and lights it ((smoke break ))
As long as you keep the topics of conversation about the task at hand while avoiding breaking the 4th wall, you are staying in character.  If some directions cannot be translated into IC without lots of writing, I use OOC brackets within a message.
Example:
"When you see its health get to 5%, burst DPS it down ASAP!"
"When you see it's near death ((5%)) hit it with everythin ya got!"
_____________________________________________________
You can even make more silly emotes to explain things like AFKs.
"brb afk 5min"
vs
emote: "*suddenly falls asleep standing up ((afk 5 min))"
"brb smoke break. be back in 5"
vs
"*takes out his pipe from his robe and lights it ((smoke break ))
