LF A Shadow Priest Dueling Guide for 3.3.5 / 5.4.8

I am quite new-ish to Shadow Priests and I'd really like to see some inside on Shadow Priests in 1v1, since they seem very strong especially in 3.3.5.
I'd prefer to see a guide for patch 3.3.5 and 5.4.8 specifically since I play those the most.

I'd especially like to see fights on 3.3.5 vs DK's, Mages, Warlocks, Rogues, Shadow Priests (Mirror) and Ferals. Other's aren't really a problem for me atleast.
I'm new to MoP so any dueling tips would be nice.

Any tips and tricks would be appreciated and I'm thanking you in advance

leow0w