I work pretty much in finder. FCPX I’m sure is powerful when it comes to organization but every time I do much of it I run into problems.
I copy all files from camera into an external work HD (then back up manually to my drive rack). Once that is done I create an event within FCPX but I create the event on the work drive that houses the media. When I create a project I also create that on the same drive. Doing this allows me to just unplug the drive and move the whole project to another computer to work on. Have had no problems with this set up.
For back up purposes I do duplicate projects inside FCPX but not the media/proxies/or whatever.
I also create ‘silent’ project and event folders on those drives and I manually move project and events into those folders to stop FCPX from seeing them. I have heard that this could cause errors but nothing has popped up for me yet.
If I need to move the project/event/files to another drive I just do so in finder and then relink in FCPX. That sometimes is a pain but it has worked ever since they introduced relinking.
My way of doing it is very barbarian and untrusting of FCPX but it is what has developed naturally for me.