creating shapes to bottom of a section

Hi everyone 

I am creating a hero section & would like to change the bottom of it to have a wavy curved effect.

I know this can be done as as a shape and then edit the bottom of it by editing the points then adding a frame round the hero section

is this the correct way or can i edit the bottom of a frame section to create the desired curves.

would creating different shapes to a section need to be created as shape elements and then nested in a frame.

thanks 

Ang