There are plenty of tools available to recover files using Windows or Linux... but for Android the apps are very limited: [...]

Rather than having wasted space in the /system partition, I've integrated various other useful apps as well - such as SMS Backup+, KeePassDroid, Authenticator, TitaniumBackup, etc. This is exactly the same as the Gapps integration, so doesn't need any further explanation.

It means that if I ever need to do a full wipe, I can install one of my ROMs and know it has everything I need to get back to the state I had it previously...

I've integrated Avast Antitheft - it works best when installed to the /system partition and this means I don't have yet another ZIP to install. As well as the APK, Antitheft can store its settings "wipe-proof' (I have different settings for each device, so copy a different file for each). Finally, I created a script to ensure that Antitheft and the settings remain even if a standard CM ROM is installed. [...]

I've integrated Google Apps so that I don't have to flash multiple zips. Although these apps contain Google's proprietary code and can't be distributed by CyanogenMod, since these ROMs are only for me there's no problem!

After extracting the Gapps package, there is one file to edit in order to include them in the build: vendor/cm/config/common.mk. E.g.: [...]