Creating MUI dialog boxs

I would like to know how to create new dialog boxs for nsis using the MUI format.

If anyone can point me in the right direction because I have been searching for the answer to this question and have come up with very lose answers.

I have downloaded and tried to use Nsis form designer but am not sure how to implement the forms I make into my script since there is a lack of documentation.

Look at the Modern UI InstallOptions examples.
Examples\Modern UI\InstallOptions.nsi

-Stu