Hiding your real IP from the Internet using a proxy and securing it through your firewall

This article is not about setting up a proxy on your browser, skype or torrents. This is easy! Just go on your application's options and setup your proxy. You should of course have access to a proxy server that ideally does not retain any log files. If they do, then if those log files can be accessed by someone then your traffic history would be available to them. So, you got your proxy server (paid or free) with no log files and you have its port and authentication (if any). You set everything up on your browser or torrent application and that's it, right?