I use a lot of decorations to create extended inverted and triangle corners. Those and regular slopes make up a majority of the rounded end caps. I also use some slope transitions. You can just take one of the designs and pick it apart if you want to see exactly how I did it. Look at the sterns because more of the rounded shape is left there than on the bow.

hey what blocks are you using to obtain the rounded shape? The circle part isnt so hard but i cant for the life of me make a balloon shape properly

Excuse me as I steal this design style because it is awesome.