Rounded finger tips? Square them off for authenticity. The Kirby Collector has been using the term Kirby Krackle for years. They had recurring articles on trying to place the first usage.
Right Ben. Square fingers are fundamental. I'm going to osmose at first. What I do is have a browsable selection of Kirby on one monitor while I draw one another. This is for two goals, getting comfortable drawing digitally, and absorbing a Kirby lesson in style.