You can reach Armour cap easily, so you want to enchant your gear with resistances.
If you want PURE tank, then put everything in health. But i'd recommend putting points in stamina too for block attacks.
Also some points in(to) stamina for running away when need be.
1. Be an Argonian. Histskin can save your skin.
2. Build and perk out Heavy Armor, Restoration, and Block.
3. Some smithing and alchemy is useful, to create Restore Health potions and strengthen your armor
4. Be a Sword and shield user, since it offers the highest defense.
5. Focus mostly on Health, but some stamina for running and magicka for healing.
6. Consider Otar for your headgear. It makes you fire, shock, and ice resistant.
7. Avoid lycanthropy, because it makes you vulnerable to physical damage. Avoid vampirism, because it makes you vulnerable to fire.