Kristin is wearing a medium length hair style that features blunt ends and long layering.  Most hair styles with ends like this are cut using a razor.  Some hair stylists will use other techniques.

To achieve this style on your own, apply a straightening cream throughout the hair and blow dry using  a large round brush.  Direct all layers down and under.  Run a flat iron over all the hair for the extra smooth finish.

Apply pomade throughout the hair for the piecey look.  Separate and position hair the way that you want.