When using RealURL in TYPO3, I prefer to set a <base href="http://example.org/"/> in the page since that makes generating links and linking CSS and JavaScript files much easier - and many extensions do not care about adding a / prefix to their links.
The TypoScript setup is easy:
config.baseURL = http://example.org/
Problem with this solution is that it works for a single host only and fails badly when having different systems - the developer machine and the live server. Now you have to remember setting up the URL on all systems correctly and do that on every change.
A better solution is to set the base URL automatically, depending on the current host header.
TypoScript constants:
BASEURL = http://example.org/ [globalString = ENV:HTTP_HOST=dev.example.org] BASEURL = http://dev.example.org/ [globalString = ENV:HTTP_HOST=dev.example.org] AND [globalString =_SERVER|HTTPS=on] BASEURL = https://dev.example.org/ [global]
TypoScript setup:
config.baseURL = {$BASEURL}