After the iphoneElite team released the new RevirginizingTool which will bring back your iphone which was unlocked to use on other networks there were many questions raised and some of them (obviously hit where).

Can I use the RevirginizingTool if I have iPhones unlocked via IPSF?
The answer is no. You cannot use this tool if you have unlocked using some other software like ISPF and also if you have never run anySIM 1.0x unlockers, or the hardware unlock this tool is useless.

Do I need to backup the iphone software or how to take backup of the iphone?

Click here to download the automated script which does this for you.

I attempted to virginize using some other method (like geohot's server)  but it failed. Is it safe to use this method now?

May be if there was no damage from previous attempts then take a backup and try again.