Some that I like are
Alexandra shortened time Alex or Andi
Helena shortened to Lenny
Dylan
Juliet (obviously not unisex but I think it’s strong sounding)
Brynn
Theo
Edie
Ellen
I tend to shy away from frilly very “girly” names as they tend to only suit girly girls. Can you imagine Ellen Degeners or Cate Blanchett or evening someone like Michelle Obama being called Poppy or Daisy? (Nothing wrong with those names- lovely names but I want something that’s more adaptable to all personality types).