"Copy" is the wrong word, but yes, I do look at how other artists draw things and try those methods out for myself. It can be colour-combinations, shading-methods, certain camera-angles, inking-methods, etc.
Drawing fanart is a good way for me to practise this, because it makes me draw stuff outside of my personal box - I draw a lot of fantasy-themed art, with swords and armour and stuff - so sometimes, it's fun for me to draw fanart of characters from modern-world settings, since that lets me practise drawing more modern fashions, etc., etc.
And as @SethJH says, copying old masters was and still is a common method of learning, at least in the world of fine arts. It was not uncommon for famous artists (like Rembrandt) to have a whole bunch of apprentices working for/with him, who not only assisted him in his own paintings, but who also learned by copying his works. The important thing is to never, ever claim someone else's work as your own.
Imitation is a method for learning; it's how we learn languages, after all, so why should art be any different?
