I already know the gender. Surprise for husband

So I couldn’t wait to find out the gender of our third baby, after 2 boys we are finally having a girl!!...I didn’t want to do a gender reveal if it was another boy because everyone wanted a girl and I didn’t want to see anyone’s face of disappointment. Lol.. but now I really want to surprise my husband since he has always dreamed of having a girl..but I’d not know how because i already know the gender. Any ideas?