I had been thinking about it for a bit and I think i have a decent starting skill set for my Sword and Shield Build
Weapon: Sword and Shield
Reason: Obvious
Armor: Rune Plate
Reason: It offers both defense and resist bonuses, which is useful for being the team's tank,
Starting Element: Earth
Reason: It has two useful channel spells which is Stone Skin and Earth Essence, especially once I get their upgraded forms. I just need to invest in some traits that reduce magic costs for channeling and magic regen to use them both.
Now for the skills:
Puncture
Reason: A basic skill with the ability to reduce an enemy's mitigation, allowing for more damage to flow through.
Intervention
Reason: It grants me a block token to further reduce damage and it has an upgrade to increase my threat, which will go nicely with Intimidate. Speaking of which...
Intimidate
Reason: This gives me a massive threat boost that makes me a more likely target for enemies. It has two upgrades that could boost either my mitigation or threat each turn. Can't decide which one is better though.
Rampart
Reason: It has a massive cooldown but allows me to gain two block tokens and can act as an emergency heal once upgraded.
Stone Skin
Reason: It gives my defense a further boost and can increase my mitigation by 1 each turn once upgraded. Depending on how I go about with Intimidate, I could get 2% mitigation every turn.
Earth Essence
Reason: Having a passive regen on hand is useful for any kind of tank. I could upgrade it to give me even more health regen or further improve my vitality for better mitigation.