Hopefully you backed up apps before flashing new rom. All you need to do now is install Titanium Backup, allow it super user privileges and going to Backup/Restore tab of the app you should see all the apps there. The ones in red are system apps, don't restore those. Can't remember for sure right now, but I thing the ones stricked through are those backed up but not yet installed. Those that are in white bold font are already installed with the new rom.
---------- Post added at 11:26 AM ---------- Previous post was at 11:22 AM ----------
Beware that somethimes, if you try to restore an app that comes with stock rom (like Notes or Memo on Galaxy S2) it can not be restored and Titanium Backup would get stuck on that restoring popup screen. You need to kill all the processes by stopping the app in settings -> apps -> running apps. You also need to stop cached process by going to Show cashed processes