All I've done is to change the default download folder in my browsers to a pre created folder on my data drive. So all downloads go there. I've also created folders for Music, videos etc and copy or rip the info to these folders.
On the C drive I right click the Music library icon, for example, select properties, select add, then browse to the Music folder on the data drive and select then apply and OK. So any music I have stored in the data drive Music folder shows up in the Music Library on the C drive. Same with the Videos, Documents etc.