Inspiration for your Character

Multi classing your thing? Tasha's adds a handful of feats for mini-multi classing. Mix in a bit of warlock or artificer for the low cost of 1 feat.
Other worldly Influence? Tasha's fey touched and shadow touched are great for fey themed characters. Telekinetic and telepathic add a bit of psychic ability.
Racial feats in Xananathar's guide one way to double down on your heritage.
Dragons! Fizban's three Gift of the Dragon feats inject a bit of dragon magic. The Children of the Dragon book above adds a dragon themed subclass as well a few other interesting options.
Subclasses? The Player's Handbook, Xanathar's Guide, and Tasha's Couldron cover most of the options. The Guide to Ravenloft and Fizban Treasury each add a couple options as well.