First of all, there will be a bit of text so I apologize in advnace
For PT Tanking, you need to make sure you are in the Tanking tree (the far left tree) and also you are using Ion Gas Cylinder which increases your threat generation (along with a few other goodies). In addition, try to stack defensive stat mods in your armor as much as you can (Def Rating, Shield Rating and Absorb Rating).
Now, be absolutely certain of 1 point - It is you who initiate an engagement. If the DPS and/or Healer initiates an engagement, the practice is to let them at it (DPS dies its tough, Tank or healer or both dies, its a wipe). To that degree, you need to generate enough threat at the beginning of the engagement to get aggro. To this end, you can try the following rotation to see how you go -
(provided you haven't called any CCs) - Delayed AOE attack, so watch for the splash damage from your dart.
(I think its call Jet Boost) - Initiate the fight
- This to generate threat and also hold it
- broken jaws tend to generate hate, anger and loathing towards you
>Rapid shot a few times
(I use Rapid shots within my rotation to Manage heat though I tend to believe not everyone does this and I'm an oddity
>Flame Burst for for a bit of extra burner
(AoE attack so may want to be a wee bit careful).
Use Rocket Punch as often as soon as its off CD as RP generates aggro. also, try to keep targets bunched up around you. in some flash points your targets will be spread out. in which case, ask the rest of your group to wait, select a distance target and grapple it in to a nearby group for the DPSers . Your Grapple will generate aggro which will pull the whole mob to you (This is on the premise you want said distance group dead, if not you can ignore this part
) for your DPSers to AOE Burn.
In Boss fights, I pretty much follow the above rotation, but also throw in Neural jolt in the mix. this makes sure I have the boss's attention at all times.
Over in the class discussion, specifically in the Vanguard section, there's a nice easy to follow guide by a fellow name Cae. I found it to be wonderfully helpful. Check it out and have a read through. What server are you on? I'm on Harbinger, feel free to send me a private message with your toon name (if you're on harbinger).