Rast, Ill combine shooter45's advice and helix's and add my own recommendation. Step #1 is practice. Shoot the ever lovin crap out of it, learn it in every way it can be learned. shoot it in the rain, freezing cold, dead of summer, at night, at rocks, into a mudhole, whatever floats your boat, but the point is get proficient with it. Once you have become able to outshoot the pistol as it is, begin the upgrades. I would start with a good set of sights, pick some that work for you. I like Heine straight 8s, but you may like bomar target sights, get some that work for YOU. more importantly, get some that work with the weapons current POI. And once fitted, its time for more practice.... Next step id recommend is a nice fire control upgrade, this will include trigger, hammer, sear, disconnector, sear spring, mainspring, plungers, pins, firing pin, firing pin spring, possibly even the safety if you dont like the mil spec style. Once fit and finished here, yup, shoot it. Anytime you change somethin, learn it all over again... lastly i would recommend the barrel be re-fit or replaced. Chances are the factory barrel is capable of some fine accuracy but just needs to be 'tightened up', keep in mind if you want a one hole gun, you shouldnt be able to field strip it with your fingers... along with a well fit barrel, link and bushing should be a properly mated slide and frame, and once properly mated the rails should be polished to reduce drag. This should round out your accurizing package only leaving functional reliability upgrades such as the lowered and flared ejection port, and if it makes you feel better, a nice one piece guide rod assembly, which i do prefer.
all your left with at this point is a bitchin refinish job and a kickass set of grips. I highly recommend a cerakote finish, matte black slide on a matte black frame with a set of ivory polymer punisher grips. should make all the guys at the shooting range jealous, especially when they see it performs on paper too..