In all of my apron making experience (I have made one) I can say that the ties are the hardest part. This apron from Martha Stewart not only solves that problem by replacing the ties with cotton twill tape like this:
which makes it cute like this:
but also makes it easy to slip on and off. You slide it over your head and then pull it tight as you tie. Kinda cool. I think I am going to take the ties off of the one apron I have made and replace it with cotton twill tape.
You can find the directions here.