Hi Neil,
I've been practising my Hammer-on and Pull-offs using all possible combinations of fingers, playing across the fretboard and back. It's going well, and I'm building speed on a lot of the combinations.
I've ran into some trouble with certain pull off combinationson the inner strings though. If my first finger isn't down then I find that, as I pull off, the pulled-off finger strikes the adjacent strings. I've tried to deaden the strings with various grips, but it doesn't lend itself to what I want to do - go across the neck and back in the smoothest and most efficient movement possible.
I think what I'll need to develop is more control over, and less movement from, the finger I'm pulling off. Do you have any practise tips or advice that could help me in this matter? I'd upload a video to show you exactly what I mean, but I don't have the facility - hope you can help.
Thanks!
Pull-Off technique
It sounds like you are executing the pull-off in a very well-practiced and deliberate manner, which might also mean "too slow". A slow pull-off requires a longer distance to load against the string, thereby running into the adjacent string. I recommend you increase the speed of the pull-off, making it more of a twitch than a pull.