Since it doesn't appear to be widely known (and this is mostly for Newcomers, but could be for Veterans as well), most of us believe that you have to lose your data when flashing a new ROM in order for it to work properly. And, to top it all off, trying to restore anything with Titanium Backup post-new-ROM-flash doesn't appear to work correctly for most of us either. And, if you don't format/wipe /data, then your phone could likely get into a bootloop or have other weird issues. There is good news, however, as there is a way to circumvent these problems and inconveniences. The following applies to all ROMs, but only if your flashing a ROM for the first time or are changing from one ROM to another. This also only applies to like-for-like Android versions; in other words, Gingerbread -> Gingerbread, not Gingerbread -> Ice Cream Sandwich. If you're merely updating your existing ROM to a newer build, you can completely ignore this Guide entirely as your data will be unaffected since you don't have to format it for an update: Take all necessary steps to prepare for flashing your ROM of choice. Such as wiping the /cache and dalvik-cache, making a Nandroid backup, and then wiping /system and /data in CWM. Flash the ROM in CWM, as usual. In CWM, select the Reboot Recovery option, located under Advanced in the Main Menu, to reboot the phone with the new ROM installed, but right back into CWM. From here, go to backup and restore -> advanced restore -> choose your most recent Nandroid backup from the list -> then choose Restore data. Head back to the main menu of CWM, and wipe/format the cache. From the main menu of CWM, go to Advanced -> Wipe dalvik cache. Next, from the Advanced menu in CWM, go to Fix Permissions. Head back to the main menu of CWM and select reboot system now. Your phone will have the new ROM installed, all of your data has been retained, and the ROM and phone shouldn't have any problems.