well one good thing i can think of tho is send them samples of ur work with resume and cover letter....its something very few ppl do...shows not only ur skills but also ur ability to be unique and think outside the box....but make sure not send in ur entire thesis or a 10 page long publication...that will just annoy them....send something short and sweet..this is specially applicable to technical fields..send em ur design simulations or code...
at the end of the day it all comes down to luck sometimes....hiring managers r on deadlines they make rough decisions at the last moment...they dont have time to look into all the efforts you put in..like the current job i have...i had like million spelling mistakes on my resume...my cell number on it was outdated....and on my interview amar gola bhanga chilo...they still took me in....and its not just some no name loser company either....so ya...id say luck has big role for entry level positions