To give practical feedback as I experienced it, it is impossible to use it effectively. Firstly, VSI experiences lag- well known. To pretend that the VSI needle is pointing to desired altitude and 'fly' it to null (at which point you should be at desired altitude) doesn't work. It means you are transferring significant attention to VSI, which is telling you nothing useful, trying to extrapolate altitude reading when you should be giving all your attention to what counts:
Altitude
Attitude
Rate of closure
Speed
Plus the others like Heading
I realised that the speed of the movement of the altitude tape is all the cue you need of VS, plus where your desired altitude is on it and how displaced your are. The only time the silly little VSI needle is useful is on final approach- you want about 800fpm, sound a warning at 1000+fpm close to the ground.
This is only my personal opinion. I realise many will not agree, but it has to be appreciated that because of the large scale movement of the VS needle, it is only practical to extrapolate on it across to the altitude tape to not more than a maximum of about 700fpm.