How to make Wordpress lightweight on server? reduce wordpress load on server?

How to make Wordpress system lightweight on server so it minimum system resources?
How to reduce wordpress load on server?

Here is what i found:
tip 1) optimize images to reduce its size, tools that can help: gtmetrix.com, webpagetest.org, tools.pingdom.com/fpt/
tip 2) Install caching plugin: https://wordpress.org/plugins/wp-super-cache/
tip 3) Setup free cloudflare.com on your wordpress site to let the CLoudflare serve the site images and other elements
tip 4) if you have larger mysql database you may try to set mysql tmp dir to the ramdisk (tmpfs), edit /etc/my.cnf and add "tmpdir=/dev/shm" line and restart mysqld. It might be risky step, learn about it before applying.
tip 5) (a VPS or Dedi server required) Use Nginx webserver instead of Apache
tip 6) (a VPS or Dedi server required) Setup Redis and serve WP using it https://www.jimwestergren.com/wordpress-with-redis-as-a-frontend-cache/ another Redit tutorial for CentOS&cPanel
In short: Nginx + PHP-FPM + APC + Cloudflare + Redis

The setup tutorial: https://vpsboard.com/topic/315-extremely-fast-wordpress-with-redis-cache/

Someone else advice: "move to nginx+php-fpm and setup nginx fastcgi cache, Zend Opcache with php-fpm and then add memcached on the backend and install the needed plugin in WordPress to take advantage of memcached."

Here is interesting project which enable one to install all above mentioned server software from one menu: http://centminmod.com

I do not use cache plugins because of I did not see to much difference in speed.

Also speed can be increased by removing unused plugins, optimizing images and java script.