If you haven't done it already, take the bow to a pro shop and have them make sure it is tuned properly. If the bow isn't tuned correctly, you'll never be able to shoot it well.
Other than that, the best thing you can do is practice. When I first began to get serious about bowhunting, I tried all kinds of sights, releases, etc, etc in an effort to help accuracy. None of it really did me much good, as I later found out, as the main thing I lacked was practice and consistency. With enough practice, you'll perform every shot nearly exactly the same without even having to think about it, and that's when you'll start seeing some real improvements in accuracy.
Now, don't go out and shoot 25 shots at a time right off the bat, as you'll end up will some severely sore (maybe damaged) muscles and you'll just teach yourself bad habits that you'll have to correct later (been there, done that too :wink: ). Just shoot a small number of arrows, maybe only 3-5 to start off with, but do it every day that you have time.