Some .htaccess security measures

Secure access to single file by IP

<Files filename>

Order Deny,Allow
Deny from All
Allow from YourIP

</Files>

Secure access to a whole directory of files

<FilesMatch ".*">

Order Deny,Allow
Deny from All
Allow from YourIP

</FilesMatch>

Secure a single file with a Basic Login

<Files filename>

  AuthName "Admin-Section"

  AuthType Basic
  AuthUserFile .htpasswd
  require valid-user

</Files>

Secure multiple files and deny access

<FilesMatch "(.htaccess|.htpasswd|filename.php|readme.html)">

  order deny,allow
  deny from all

</FilesMatch>

Allow only some files to be accessed

order deny,allow
deny from all

<files ~ ".(xml|css|jpe?g|png|gif|js)$">

allow from all

</files>

Prevent directory browsing

Options All -Indexes

Disable hotlinking

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www.)?YourDomain [NC]

RewriteRule .(jpg|jpeg|png|gif)$ - [NC,F,L]