What is the proper way to create hook?

[oxilor]

Cannot create hook. Need help!
For now one recorde is created in 'ps_hook' (name = 'nav', title = 'Navigation', description = NULL, position = 1).
hook 'HOOK_NAV' => Module::hookExec('nav') is added in header.php.
{$HOOK_NAV} is added in header.tpl.
There is also a function hookNav($params) in entire module. Next I want to set a module position in new hook in admin, but there is no "Navigation" in proposed list hook...