Firstly, develop your own style. Some new designers think they'll get better opportunities if their style reflects other popular looks in the world of surface design. However, in my experience, it is the artist who brings something entirely unique to the table that gets the fast and enthusiastic "Yes!" from a potential licensee.
Secondly, and this relates to my thought above, don't fret over how you will deliver your artwork at this point. Licensees are used to working with clean digital printouts, with hand-painted designs and everything in between. Focus on developing your unique voice and your method of artwork delivery will develop out of your style and out of the business relationships you build with licensees.