Good equipment is important, I agree with that, BUT, IMO, the most important item for good shooting, is TIME. You need time to practice, practice, practice. To be really good, you meed to MAKE time to practice. You need time to shoot slowly, so that you can determine why ARROW X did what it did. Time to make changes slowly. NEVER change more than 1 thing, be it equipment, setup, stance, release.
Back when I was shooting competitively in the BHFSL division (Bow Hunter Free Style Limited - "pins and fingers", finger release with tab or glove, 5 fixed pins, Max 12" stabilizer), I routinely shot in the high 290s, hitting 300 4x in competition. Got beat out on Xs every time I shot 300. Just the caliber of competition I faced in Texas.
That's not said to be bragging, but is necessary for background. To shoot that well, I would shoot over 300 arrows per day 7 days a week, unless it was pouring down raining. During INDOOR season, 80% were 20 yard shots. I still shot outdoors 1 or 2 days per week. During OUTDOOR season, the percentages were reversed. Distances were 3 yards to 80 yards. The people that were beating my ass all the time were doing that much or more. I lived down in south San Antonio, below Kelly AFB. The nearest range was 26 miles away on the far north side of SA. I would drive there every day after work. I shot in 2 indoor leagues and at least 1 tournament every weekend.
I also probably could have won more tournaments, but I refused to shift up to "telephone poles". Large shaft diameters give you more slop for "line cutters". The arrows I shot were 18s (0.28125") indoors and 20s (0.3125") outdoors. That's in 64's of an inch shaft diameter. The maximum shaft diameter allowed is now 27s, or .422". Someone shooting a 300 with 18s - 22s impresses me a hell of a lot more than someone using 25s - 27s.
The second most important thing you need for shooting well is PATIENCE. Shooting fast leads to lower scores. I don't mean shooting glacially slow, taking the maximum of 1 minute per arrow or 5 minutes per end like some arrogant assholes do in tournament, just because they can. I mean that you must have patience and CONCENTRATE on EACH shot to make sure you do the same thing each and every time. I have seen outstanding archers shoot 300s using no more than 2 minutes per end. I have seen crappy scores come out of the glaciers.
The third thing you need is DEDICATION. You MUST be willing to dedicate ALL your spare time to archery. Shoot every tournament you can. Shoot 1 tournament on Saturday and find another for Sunday. Shoot in a league to simulate competition and have someone to shoot against. Shooting against someone else, no matter how crappy they are THAT NIGHT, forces you to concentrate to do the best you can every time.
A little "dedication" story. When I got transferred to Newport RI for Navy Department Head School, I found the Tiverton Rod & Gun Club just off the north end of Aquidneck Island. They also had archery I&O. I would go up and shoot with them on when I had time from school. One day, the guys I was shoot an outdoor round with were debating which weekend shoot they were going to go to. They were also trying to decide if they were gonna "go all the way to New Hampshire" for the All New England tournament. One of the upcoming weekend shoots was just over the state line in Massachusetts, about 14 miles away on a Sunday. The other one was on Saturday, just over the Narragansett Bay bridge in Warwick, about 30 miles away. The ANET was in some little town in NH about 140 miles from the Naval Base at the extreme south end of the island. I had been pretty quiet during all this discussion (unusual for me

) and one of them asked me what I was going to do.
I said, "I'm gonna shoot Warwick on Saturday, MA on Sunday, and I'm going to NH the next week. Y'all don't know how good y'all have it up here. In Texas, we can't have a shoot the same day as some other club that is within 150 miles of each other. Down there, I'd drive 90 miles south to shoot in Corpus Christi on Saturday and then drive home, and then to drive to Austin or Waco, 100 or 160 miles north away for Sunday. And y'all are bitching that the Regional tournament is over 100 miles away this year." There was a reason I waxed everybody's ass every time I could go shoot.
The fourth thing you need is an "I don't care if I get beat as long as I beat my last score" attitude. Don't worry about what the other quy (or gal) is shooting. If you concentrate on beating yourself, the good scores WILL happen.
As I said, good equipment helps, I can attest to that. I was routinely shooting around 230 with my "Bear Whitetail Hunter" (now an ancient piece of junk), went to a PSE hunting bow and gradually crept the scores up to 270s. Got a custom Viking and the first time I shot it, I broke 290. Sweet bow.
But your best equipment still needs to be you and your attitude. Money can't buy those.