Hi, thank you!.

I use sometimes, other times not. Use mostly when I want a very specific or tricky pose. I do think it is useful to use references for practice and studies, and don´t worry if at first it doesn´t look “perfect”, takes a lot of practice and patience, as everything.

A little thing i would say is that at first don´t try so hard to “copy” a hand or a foot or whatever, maybe start with the general directions and proportions, try to understand the basic masses and forms, try to see it as geometric shapes, is a thing of relations between points in a plane, use synthesis, don´t get stuck in details. After you get that, it is way easier to go to a more organic and detailed work. 

You could also try to draw from life, draw yourself or ask for someone to pose. 

And regarding using references in general, I think it´s good, but it is also good being able to detach and work without them,  not depend completely on it, so for that you just need a lot of practice, you can practice with references sometimes and others without.