How to protect your file content using htaccess?

# Prevent Apache from serving .htaccess files:
<FilesMatch "^\.htaccess">
    Order allow,deny
    Deny from all
</FilesMatch>

How to enable and disable the PHP magic quotes directive?

When the magic quotes directive is enabled, PHP automatically escapes 
data from HTTP GET and POST requests and cookie data. For example, 
if a user types “hello” (with the quotation marks) in a form, PHP 
automatically escapes the quotation marks and stores the value as 
\“hello\”. To enable this functionality, use a text editor to 
modify the magic quotes directive in the php.ini file as follows:

magic_quotes_gpc = on

To disable this functionality, modify the magic quotes directive in the php.ini file as follows:

magic_quotes_gpc = off

How to enable and disable the PHP register_globals directive?

When the register_globals directive is enabled, PHP creates variables 
automatically from HTML form parameters and cookie data. 
To enable this functionality, use a text editor to modify the 
register_globals directive in the php.ini file as follows:

register_globals = on

To disable this functionality, modify the register_globals 
directive in the php.ini file as follows:

register_globals = off