There is no definite answer. Each network has its own rules regarding Tor and proxy servers in general.
For Freenode, you have to:
- Set up your IRC client for SASL authentication;
- Connect to the Freenode hidden service
More detailed instructions are at staffblog
The Tor cloak will be applied automatically. However, you mentioned that you already have a generic
unaffiliated/* cloak, so Tor should not be necessary on Freenode.
(Nevertheless, configuring SASL is a good idea, to ensure that your cloak – Tor or not – gets applied before joining channels.)
Alternatively, you can connect to IRC through a (proxy) server. Some people rent their own VPS and configure it as a proxy; others settle with an account on a public "shell server".
Whichever of these you choose, it is very easy to tunnel IRC over a generic SSH 'shell' connection.
Some people prefer to use bouncers instead – it's a kind of IRC proxy server that, in addition of hiding your actual address, allows your session to stay online 24/7 even if you disconnect from the bouncer. (IMHO, not much point in that, unless you want to keep complete logs of a channel.)
(To be honest, I do not see any point in hiding your address just for the sake of it. It's not like someone can crash and burn your PC or your house just by having the IP address... It's okay if you wish to remain anonymous and care about it, but not if you're simply scared.)