A HUGE part of tanking comes down to experience, comfort level, and keeping a calm head... Oh, and don't forget having skin thicker than a M1 Abram's tank. You will be the first to get blamed, the last to get thanked, and the only one to get yelled at most times. Learning runs is VERY important... Learning the limits to which people can heal on their gear/skill, understanding not every party is going to be a speed run if you get 2 single target specialists, and one important one most tanks forget... UNDERSTANDING YOUR OWN LIMITS AS WELL. This is a very big part of being a tank... I play all 3, and I will not deny I overestimate myself time to time on the "everything is going great" moments. Comes back to bite you in the keister really quickly. A good way to start as a tank? No joke, run things as DPS, watch the tank carefully, and see how they pull, what they understand limits are, and hope they are respectful, many can be rather toxic.