I came to realize that I have thousands of designs and use the same ones over and over. I almost always use my candi font from 8claws. It works well for girls of all ages and they love it. The photo doesn't do justice to the awesome end product which is smooth, bold and gorgeous.
http://www.8clawsandapaw.com/candi-embroidery-alphabet-set.html
I have a 3 year old girl and I get invited to a lot of birthday parties. Right now my favorite design is the free princess hat from planet applique. People love it. So simple to do.
http://www.planetapplique.com/free-designs/princess-hat-applique/prod_179.html
Sometimes I made an experiment with a new design and it ends up in a mess so for customers I only use well tested designs ;o)
Greetings, Bettina