Don't import the media into your library (select 'leave in place'), don't create optimized media, and don't create proxy media. Just use the raw source files. I know it goes against common "X" thought, but some of my projects contain over 20TB of video and I just don't have the time or drivespace to work that way. I used to import the media into the library, but that created problems and delays when using motion animations in my edits. Example - You have a fancy animated open or something that you've created in Motion, and you've imported it into your project for use in your edit. Then you've got to go back and make a change in the open, so you bounce into Motion, make the change, and re-output. if you use the "leave in place" option, anytime you make a change to the animation and overwrite the source file, it automatically changes in the X timeline. If you use "copy to library", anytime you change a file, you have to re-import it and delete the previous version. Total PITA.
I create a folder on my external drive, dump all the media I am using into that folder, and then edit using the media in that folder. When I am done, the library and the source-footage folder are offloaded to archive.
