First off shield the healers keep them shielded...... as for aggro in pvp there toons and not AI to get aggro you have to be the biggest threat if you have aoe etc use them those hurt everyone and draw attention to you. Also go for there healers always look for them thats a great aggro builder........ yes CC donot break...... defence wise use your slowest cooldown constatnly like kinetic shield for shadow use there slower cooldowns such as deflect once you have two or more on you to break stun chains use any force wave like ability you have dont run if there around you locking you as soon as you get a half a second respite pop the wave it knocks all back and down and gives you a respite.... build defence etc shield you name it gives longer life utilize aoe as much as possible and stun or knock down as much as you can if your tank your not the killer you are the aggro point the cannonball per say let the killers kill your job is to annoy everyone to no end this is my advice...

May the force be with you

I agree with Forcestrike and with what you said. Another key thing is to not get discouraged. I have run in many groups where the tank was chastized for breaking CC, not grabbing agro back, losing agro to begin with and such (not in SWTOR but in other games I have played) and while yes it can be a pain in the tush to wipe multiple times, the only way you are going to learn is through that practice. So my key advice is this:

Dont get discouraged
ask questions
learn from your mistakes
cherish your healers
have confidence in yourself.
mark targets
if you notice something going wrong announce it. Much better to try to adapt rather than wipe and say, "yea I thought that he was going to do that"

oh yeah and:

PS.... Always keep moving weaving ducking...

I encourage the world to be more Ducky 

love that edit DUCK lol ducking great one yes he is correct never get discouraged try it all and if you see me in game hit me up ill WZ with you and show you some tricks np all you have to do is let me know:-)

This is what i have W is forward S is backward E is right turn have to set it...Q is left turn have to set it....R is target nearest enemy.....F is target nearest group member or ally...Target while moving by just clicking the R key to pick nearest target and wack them one if you have a specific target just run up to them and push R nearest enemy aquire the target annoy them and at any time use the same method with target group or ally its how i never stop moving im not picking on one person im picking on them all whoever is closest gets the picking on.