CSC isn't too bad: the main parts are just a couple of XML files. There's some documentation on here you can dig up, many variables have self explanatory names, and so on.
If you're using a multi-CSC ROM, just make sure to modify the active files.
Smali, on the other hand...
My phones: Galaxy Note II SGH-T889V (with LTE enabled
/ ext4 SD card support on TouchWiz ROMs
Previous phones: Nexus S GT-I9020A, Galaxy Gio GT-S5660M (Arpeggiomod ROM
/ Discussion, stock rooted ROM
Phones for which I play "tech support" for family and friends: Galaxy Nexus GT-I9250, Galaxy Q SGH-T589R, Galaxy 551 GT-I5510M, LG C-800G Eclypse, Motorola XT-1032 Moto G
- Level 8