I think there's something so charming about a big fluffball of a pom pom (or three) atop a simply wrapped gift. Keep the tying-off yarn ends long and braid them together...
Or, make them extra-long, and tie around the box like ribbon.
Or even wind multiple colours around the box creating a colour blocked look before topping with a big beautiful pom pom. I used a hair clip to attach the pom to the box - you can't see it (clever!) and then recipient can wear their new pom friend once the gift is unwrapped.
I used our new Pom Pom Makers to make these - the large set is perfect for pompoms of a gift-topping size.