Pretty much depends between garrote/cs if its something that can cast or just melee.
Also depends if you're planning to blow much on a hard open bomb.
Hard open smokebomb:
Premed in stealth recup then @ 100% energy open cs/garrote>hemo>evis>dance>amushx2-3 and evis again all in smokebomb with ap trinket proc'd (early recup before opener so u dont have to do it during burst and get energetic recover for about 8-9s off the recup)
Opener without cds:
Premed>garrote/cs>hemo(at 5cp at this point)>recup> backstab to 5 snd> keep backstab spamming!
Try to keep snd and recup up 100% of the time but prioritize the recup.
Also cs/ks is good if you're going to swap to a rogue in dance/bomb with all ur cds, same deal with shit like wars/hunters etc..
While garrote openers may be alot better for you, your DR's and your "rotation", CS openers have so many positive aspects when you consider your partners - for one, if you garrote and shiv right after for crippling, there's still a delay where (if mounted, or has a partner rooting you), you might have gotten nothing nothing out of the garrote opener. on targets like locks/mages/dk's you should definitely open with garrote, but if we're going healer I usually go CS > hemo > Dance+garrote and then save the kidney for Inner Focus/Freedom/Aura Mastery/whatever. Against Druid and Shaman healers where you wanna prevent hots or ES from coming out for as long as possible you could end your dance with a second garrote and then KS right after that.
But basically alone, your best opener is usually garrote. If you're going for the best positioning of your team and your target, go for CS imo.
Casters = garrote+kidney for 10secs lockdown @ 45 energy
Melee = CS+kidney for 7secs lockdown @ 40 energy VS Kidney for 6 secs lockdown @ 0 energy
In short, against casters and DKs sometimes, open with garrote usually. Against melee usually, while not CSing appears far superior most of the time, CS into Kidney is still extremely useful, e.g. when bombing, preventing charges/grips/stuns/gouges etc. Sometimes its good to backstab instead of hemo just to get opening pressure. Of course, a lot of this depends on your comp, a rogue in RLS vs a rogue in RMP will open differently.
As far as premed, I almost always use it with garrote. With CS/Ambush, if I know I'm going to dance early, I'll save the premed.