Make package folder and subfolders like DEBIAN usr/local/bin usr/local/share ...

Make DEBIAN/conrol file

Make usr/share/icons/someicon folder

Make icon inside usr/share/icons/someicon folder

Make usr/share/applications/your-application.desktop file

Place your script into usr/local/bin/

#### replace package-folder using correct folder name

Open terminal inside package-folder

find -type f -print0 | xargs -0 md5sum | tee md5sums 

Calculate size  

du 

Open Pluma and remove ./ in the front of md5sums and copy the correct md5sums to DEBIAN/md5sums file

Run outside package folder

sudo chown root:root -R package-folder

find package-folder -type d -print0 | sudo xargs -0 chmod 0755

sudo dpkg -b package-folder package-folder.deb