Daniel,
I agree with Brian. Short game will get anyone to the next level. Getting it close from 125 and in.
A lot of it come down to how many
clubs do you have to hit between 125yard down to 60 yards. I hear of golfers brag they can hit thier SW 125 yards. Why would you want to? The idea is to have many weapons 125 and lower. If you gauge a PW at about 125 - 130 and carry 3 other wedges you can take a full swing and get it close and accurate.
Everything 60 yards in is a pitch or chip. These shots require a lot of practice. Developing shots around the green requires a lot of practice. Putting with a fluid tempo requires practice. All these things will lower you scores closer to scratch.
In your practice efforts, keep a journal. When you go to the range work on specific things. Have a plan, and stick to it. When you are on the range, don't just hit balls, rehearse your pre shot routine on every shot. Aim at a different target for every shot.
Play 18 holes on the practice range. Get a score card and hit your normal shots to the holes. Visualize the shot.
These are some practicing tips. I have been at scratch a few times as time permits practice. The lowest I have gotten is a plus one. That was a few years ago before my elbow surgery. I am begining to get back to that level again. Daniel, it's just taking it to the next level. If you want some reading to help get you there anything by Mike Rotella is good.
Hope this helps a bit. If you want more practice routines don't hessitate to ask,
GolfBald