a hard worker (whose not willing to do it for free just to screw everyone else over), who is enthusiastic and goes above and beyond what is expected, will stand out and impress your bosses/potential bosses.
I would avoid putting such cliches out there in aviation. Ultimately in life that holds true however in terms of the aviation industry there is alot of luck involved, and I have witnessed some really good, well qualified pilots get screwed over whilst some pretty ordinary operators who had connections in their younger years just breeze through. In the end everyone ended up where they wanted to be, but I wouldn't say that just being a hard worker in aviation necessarily counts for anything. I think it is a myth that needs to be dispelled because it will only lead to bitterness. This becomes a bit of a issue as all airlines work along seniority lines so if your goal is to be an airline pilot once you get in there is very little you can do to accelerate your career. So getting screwed early in your career can actually have a detrimental affect on your entire life.