I've captured a lot of mini dv tape footage in adobe premiere which now sits in the library box in the bottom left. I've logged time in and out points of clips I want to keep with pen and paper. Should my next step be to do that by creating sub clips? Or is there another way?
Workflow is really up to whatever works for you. Unfortunately, you kind of did things backwards from the workflow I would have used.
With mini-DV tapes, the fastest thing I've found is to do the clip logging with the batch capture tool and then run a batch capture to have each clip captured as an individual file. It does take a little bit of practice to get good at using the batch capture tool for logging, but it makes it easy to recapture a particular clip down the road and organizes clips much more easily for you.
After the fact, your best bet is probably just to drop each clip in its own sequence or simply insert them all on to your timeline and work from there if you have a decent idea of how you want the rough edit to look.
You could also split the clips if you wanted as long as you are using DV format which will not lose additional quality in each additional export. It really comes down to whatever will be the easiest for you to work with though. Everyone can be a bit different when it comes down to how they want to organize their stuff.