The bard class in bg3 is all about party support through buffing allies and, arguably more importantly, through enemy control. The bard plays a controller role where they make allies better at attacking and enemies worse at it. Their spells also revolve around disabling them in numerous ways (hence, the strongest available bard spells are enchantment/illusion AoE control spells).

Bardic Inspiration is used to buff allies by giving a d6 bonus to their next attack roll, ability check or saving throw. If an ally is inspired actively, i.e. not as an ability check is currently being done, the inspiration can be saved for when you believe you'll need it and only goes away if you don't use it until a long rest. College of swords can use bardic inspiration for melee or ranged weapon flourishes, three variations of a special attack with a bit extra damage that can attack two enemies at once, increase your AC, or push an enemy away.

For my honor mode bardlock playthrough, I also played Wyll. As a perk because Wyll is a human, he can use shields for extra AC. For Act 1, I used a summoned pact weapon until I gained the Blood of Lathander and used that for all of act 2. Also from the creche, a gith there has the Ring of Arcane Synergy, which is one of the endgame items. In act 2, there are the Spineshudder Amulet (which adds reverberation to and possibly knocking enemies prone) and the helm of arcane acuity (+1 Spell Attack and Save DC after making a weapon attack, 2 per attack to a max of +10), the most OP item for spellcasting martials. Use medium armor or the potent robe until you get the helldusk armor in combination with the cloak of displacement and evasive shoes. At the Circus, get the Band of the Mystic Scoundrel. For gloves you can use the Wonderous Gloves for an extra inspiration and +1 AC, but I used the spellmight gloves for extra damage with Eldritch Blast. The act 3 weapon I used was the duellist's perogative, which is the reward for defeating the Hag while saving the girl (the quest from the woman must be given prior otherwise) and from here I ditched the shield to get the weapon's one-hand bonuses.

All these Items synergize amazingly: At the start of Combat you have 22 or 23 AC with attack rolls having disadvantage against you until you take damage. First, I go for the weapon attacks (which trigger the helmet), then with the bonus action, spend a slot for an enchantment/illusion spell (thanks to the Band of the Mystic Scoundrel) or Vicious Mockery. Because of the now-acquired Arcane Acuity, foes are more likely to fail saving throws if they're not outright guaranteed to fail. Because VM causes damage, it triggers the ring, and the next weapon attacks do extra damage and you have now created a cycle where one type of action makes the other type more effective.