I like to use portrait tokens for NPCs and foes to add visual interest for my players. The effect is increased if each orc, skeleton, or man-at-arms is distinctive, with more variation than just a different-colored crest or shield. My artwork starts with images generated with MidJourney AI. The prompts never include image prompts of other artists' art, or mention of living artists' style. In addition to other post-generation adjustments, I always do some paint-over to improve the image or make it better match my vision (including making each token of a particular monster match well with the others of the same species.)
Check out my Patreon page for more tokens, portrait versions of some of the foes in these token packs, and other fantasy RPG artwork. Some are free, some are for patrons only.