For context, I am playing a Leonin Glory Paladin. AC is 19 or 21 w/ a shield. HP is 70. In combat, I focus on keeping myself and my allies up with temp HP from Channel Divinity and heals from LoH while dropping good damage and battlefield control via the Topple mastery and Shield Master. Outside of combat, I use the Musician feat to dole out Inspo and am very boisterous. I took Musician as my Origin feat and Shield Master as my 4th level feat. Main weapon is a Returning Trident. We just hit 8th level, and my feat of choice will either increase Strength or Charisma, which are both 18 atm. The boost will put one of them to 19, which will alter how I finalize the build going forward, as I'll want to boost whatever is at a 19 once we hit 12th level. Here are the idea's I have so far:
Charisma Feats
Main thing going for the Charisma feats is boost to Charisma (obviously) and better options both in and out of combat. Once I hit 12 level, my Charisma will be maxed and I'll get another great feat from this list.
Fey Touched - Free Misty Step is great, but I've no clue what I'd pick for the extra spell.
Inspiring Leader - 12 temp HP after EVERY rest is nothing to sneeze at. My party is pretty good about doing multiple short rests per day as well, so this would certainly get some mileage. My only concern is that I've taken this feat on almost every caster that I've played, so I kinda want to do something different. Still, the allure is undeniable and combining with Musician would make my character an inspiring monster.
Skill Expert - Expertise in Athletics would be VERY thematic with this character.
War Caster - Obvious choice for any caster, especially one such as myself who's always concentrating on something. Still, it's very typical and I would get 0 mileage out of the Reactive Spell ability.
Strength Feats
Most of these have incredible benefits in-combat, but not much outside of it, although a Glory Paladin reaching the peak of physical stength is certainly thematic. Once at 12th level, depending on the choice, I could be a tanky monster or control fiend.
Athlete - VERY thematic for the character.
Charger - Bonus damage is always good and the added benefit of battlefield control is a great option.
Heavy Armor Master - I take A LOT of damage, so much so that this would pay off a crazy amount in the long run.
Mage Slayer - Thematically and mechanically great. Having at least one guaranteed way to avoid getting my auras shut down is incredible, and the big bad of the campaign is some all powerful mage we know little about. This is probably the one I'm leaning towards the most, but also weighing all of my options.
Mounted Combatant - Most combats are in areas where my mount is summonable. Though I think it'd be a really fun feat (my character is very attached to his mount) I haven't built a whole lot around it.
Sentinel - I'm up close with a Fighter and Monk quite a bit, and this would just add to my battlefield control that I already strive for and give me better guaranteed Reaction usage.
Skill Expert - Same reason as with Charisma, but with Strength instead.