So you want to use CForm (form builder), but need to preload dropdowns in a form? It's simpler than it seems.
You got your CFormModel, CForm and the actual Form, right?
Let's say you have the typical State -> City dependent dropdowns, so you would want to load the from with the State and City selected.
If you are hosting Yii behind a reverse proxy, for example nginx, and you are having issues with your logs showing the proxies IP, or the urls being created arn't being created for SSL because your SSL certs are located on your reverse proxy instead of the Yii server, this code may be able to help you. I placed them in the very top of Yii's entry script, index.php