What to backup before unlocking bl and flashing rom (cm)

I looked around but didn't seem to find a decent list of everything I should backup before unlocking bl on my XM (C1905) and flashing cm.

I came across the following items:
+ TA: backup for keys using Backup TA . Can anyone confirm this even still works since it is unmaintained.
+ appdata: using Titanium
+ nandroid: I need cwm for this, right? And for cwm, I have to unlock bl so there is no way to make nandroid backup without unlocking bl first?

Is this everything I need if one day I decide to want to go back to the current state of my phone?

Thanks for any help

Current phone information and state:
C1905
official rom build 15.4.A.0.23 (JB 4.3)
rooted
odexed
locked bootloader (but unlockable)