Use both hands one on the torch (obviously) but the other on the back of the torch neck steadying it... if you try & do it one handed you'll be all over the place (as your girlfriend might have mentioned ).
weldequip
You're probably too close for the lens on your camera phone to focus. Either use the macro mode if there is one (the icon usually looks like a tulip) or stand further away and crop (make sure you use the biggest picture size for best results). If there's not enough light, or you're too far away for the flash (if any) to work, you'll get grainyness.