To redirect from
 - http://www.domain.com
 - http://domain.com
 - https://www.domain.com
im using the following (apache)htaccess:
<IfModule mod_rewrite.c>
   RewriteEngine On
   RewriteCond %{HTTPS} !=on
   RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1 [R=301,L]
</IfModule>
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{HTTPS} !=on
    RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
    RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L]
</IfModule>
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress
This works, but I think it's not the best way. The first two sections would still be to combine, but I don't know how.