I can only add 2 things to Digital Dan's list
1. Ammo TESTING. Only your rifle can tell you what it likes. Equipment and ammo are plenty important, but flushing out the ammo your gun likes is a big advantage.
2. Practice! Only you can learn for yourself how to get and manage a proper weld, natural hold, read the wind, manage your trigger (and know it intimately), etc. Maybe you can pick up how to shoot between your heartbeats, and some other skills.
Of course there are more, smaller tips (and plenty that I don't know about I'm sure) but that will get you started.
ps - maybe you can set up some really big pieces of cardboard at first, just so you can see your POI at unfamiliar ranges. Spray it white, that kind of thing...
