I wanted some help, suggestions and/or tips on soloing dungeons (mostly level 80 heroics) as a shadow priest. I had some trouble soloing UP my first time as shadow, and also died on several occasions. If it matters, my armoury is Randgris on Earthen Ring (I can't post link yet, I need to post more).
First, if you're interested in soloing content you need a proper spec and glyphs. http://www.wowhead.com/talent#bfroZZ...z0fo:skMVbM0Vz
Use your Power Word: Shield whenever you can, be ready to spam some Flash Heals if you're dying.
Pop Shadowfiend and Fade, this will make the Shadowfiend tank the adds/boss.
If you're low on mana use Hymn of Hope + Dispersion, that's around 40% mana back. If your mana is ok, treat Dispersion as a defensive cooldown (a really good one).
On trash use Shadow Word: Pain on as many targets as you can, if possible add Vampiric Touch, use 2/3x Mind Spike + Mind Blast on targets with low HP, finish them up with Shadow Word: Death.
In some instances it is useful to use things like Shackle Undead or Mind Soothe, to CC/avoid mobs.
Don't know about that, but i think it is possible to Mind Control a mob, so the rest of the pack kills it/ damages it significantly.
Obviously Fear is the way to go most of the time.