Titanium is a good file backup/restore, but it's not going to bring you back from a boot-loop or restore you back to your original setup so you can get the next OTA update.
Download
Droid X Recovery Bootstrap from Market ($2).
Open Recovery, tap the top button. It should say "success", meaning it's ready to go. IF you press the bottom button, it will go into the recovery, where your volume keys navigate the cursor up/down and the camera button is your "OK" button. Your 3rd button on the bottom of your phone is your "back" button.
Download
Rom Manager from Market. This is an easier way of backup up your phone, but it still requires a working Recovery to operate. It also can install Roms you've downloaded. To back up your phone, open Rom Manager, choose "Backup Current Rom", then edit the name to give it something that means something to you, but
do not use spaces. This is an old pic, but it gives you an idea of how I name my backups.
You could name it by rom type like, "Apex_no-theme_12_16_2010".
Make sure you have a backup of your stock, no-rom, no-theme, no apps removed setup, so you can get the next OTA update.
You can never have enough backups!