Tip of the day:
One of the most commonly asked question by students is that they love character design but don't know how to begin. Well, the only advice is... Just start! Once you start doing it. You will come across problems. And those problems will tell you what solutions to look for. Simple!
P.S. Just Don't do copy sketching, but attempt to create designs based on live reference or photos. Give yourself a character design brief and then try to find the design solution to it.