Not to get confused, let us recapture all steps we have taken to build our binary Debian package.
Prerequisite files:
one or more binary executable or shell script files
a man page for each executable file
a 'control' file
a 'copyright' file
a 'changelog' and 'changelog.Debian' file
Setup temporary 'debian' directories:
create 'debian/usr/bin' directory (or wherever you plan to place your executable files)
create 'debian/usr/share/man/man1' (or whatever section your man page belongs into)
create 'debian/DEBIAN' directory
create 'debian/usr/share/doc/<package_name>'
make sure all sub directories of 'debian' have file permission 0755
Copy files into temporary 'debian' tree:
copy executable file into 'debian/usr/bin' directory (or wherever you plan to place your executable files)
copy man page file into 'debian/usr/share/man/man1' directory
copy 'control' file into 'debian/DEBIAN' directory
copy 'copyright', 'changelog', and 'changelog.Debian' files into 'debian/usr/share/doc/<package_name>'
gzip man page, 'copyright', 'changelog', and 'changelog.Debian' files with option '--best' inside the temporary 'debian' tree
Build and check binary Debian package:
invoke 'dpkg-deb --build' using 'fakeroot' on the 'debian' directory
rename resulting 'debian.deb' file to its final package name including version and architecture information
check resulting .deb package file for Debian policy compliance using 'lintian'