Link to this build: 51 Riftstalker / 8 Ranger / 7 Bard
This tank spec will provide you with the maximum health a rogue can have. I will also suggest what runes to wear for maximum health as long as you do not need more toughness or hit for the dungeon or raid you are tanking in with this spec. You can use this spec anywhere you want, however there will be fights where max mitigation is much better than max health. You will want to have this spec and the other if you are going to be tanking a lot.
You will obviously gain more health as you get more geared however you will not always be choosing gear with more Endurance over other stats such as Deflect, Dodge, etc.
You also have Instigate to grab threat off someone or to make sure you have threat right away depending on the pull or how you pull it. This has a 8 second cooldown and 20 meter range.
You can choose not to macro these together and have them separate, remember that Shadow Blitz is already in the Shift Threat Macro too and you may want to remove that depending on your preference. If you have the Riftstalker Crystal, every time that you use Shadow Blitz it reduces your damage taken by 10% for 5 seconds.
You also have another AoE threat called Planar Attraction, this has a ridiculously 1 minute cooldown and pulls up to 5 nearby enemies to you. Do not macro this though.
Memory Capture > Flashback
You will likely find yourself rarely using all 3 of these abilities, Shadow Warp and Memory Capture/Flashback will be very useful to use sometimes but not nearly as always, you can keep up your buffs simply be using the Shift Threat Macro every 10 seconds. These will just give you greater mobility, especially if you are going to kite a mob or need to use them for any other reason.
These are the greatest cooldown a rogue tank of course has. Defer Death can save your raid in a lot of ways, and when properly used. The same goes with Planar Refuge and sometimes Scatter the Shadows depending on the fight, what you are using it for and if the damage can be ignored with it. Not everything can be such an example as on Maklamos the Scryer, you cannot ignore Crystalline Desolation with this.
Physical Wellness, an increase of 1500 HP to your raid for 20 seconds, will be more useful for those fights where your raid is not as geared, when heals are going to be needed for a lot of damage about to be taken very soon and what not else. You will not always use this and this will be dependent on the fight, if you are in Hammerknell Fortress you could use this on Inquisitor Garau or in Infernal Dawn on Ituziel just when a lot of AOE damage comes out at 33% to help your healers a little.
You will not always need to cast Fanfare of Vigor yourself if you have a bard to cover this in raids and or another greater endurance buff from another class.