Correct way in new versions of nginx

Turn out my first answer to this question was correct at certain time, but it turned into another pitfall - to stay up to date please check Taxing rewrite pitfalls

I have been corrected by many SE users, so the credit goes to them, but more importantly, here is the correct code:

server {
       listen         80;
       server_name    my.domain.com;
       return         301 https://$server_name$request_uri;
}

server {
       listen         443 ssl;
       server_name    my.domain.com;
       # add Strict-Transport-Security to prevent man in the middle attacks
       add_header Strict-Transport-Security "max-age=31536000" always; 

       [....]
}

Some ideas:

1. Lower your fpm settings then increase as needed:

   pm.max_children = 10 # concurrent children's
   pm.start_servers = 2
   pm.min_spare_servers = 2
   pm.max_spare_servers = 4
   pm.max_requests = 300 # till restart

2. Lower the nginx settigns.

3. Install pecl-apc(Debian package is php5-apc).

4. Update your php/nginx version to latest stable

What is your server spec?