Remember to check and recheck before you place the card in and turn it on. By checking the resistence before and after can help deterrmine if you've made a mistake. Some may have you vmod and then test by placing the card in and powering it up. You don't drive blind, so don't mod blind.
Unlike the Pencil Vmod using the VR takes good soldering skills. I can contest to that and even though my soldering is rusty I still managed to do a few until I had slipped on my own card. Needless to say accidents do happen. So please take your time and be careful. But above all be safe.