Generate headbands of any size, and you can add cute ears to them if you like.
UPDATE: Now with hearts!
Measure the head of your victim headband recipient and use the customize to generate an appropriate headband. Optionally choose an ear style.
There are no STLs, to download, just use the customizer. Just beware that customizer (and openscad) are very slow to process this model because it uses the minkowski() function.
The headband prints in one piece with no support. If you specify very tall ears, the overhang angle can become a problem, you can compensate for this by using thinner slices.