To get better at golf:
1. Understand your golf swing and what you would like to change to influence ball flight and consistency. Choose where to start. Work on one thing at a time.
2. Create a practice plan with specific drills for the aspect of your swing you want to change.
3. Do repetitions and slow motion swings indoors and check your reflection in a mirror or window for feedback.
4. When you hit golf balls, alternate between rehearsal feels or your drills and hitting a shot. Less than full power is preferable.
5. Check your progress frequently with video.
The process listed above is how excellent golfers improve their swings. Contrast this with the endless cycle of tips, experimentation and searching that most golfers spend their time trying. The great majority of amateur players do not improve primarily because they don't know their own swing and it's flaws. "Understand your golf swing" was listed first here, because none of the steps which follow have any relevance unless the player knows what to attempt to modify.
This, or a process very similar is how good players get better. My job as a golf coach is to help the golfer understand his/her swing and to assist in creating a plan for improvement. The plan always includes drills and checkpoints. If you focus on one or two things to improve and work intelligently on those items, you will get better. It will probably take a few thousand reps (Which is another reason most don't improve) but the trick is to know what to work on, know how to work on it and put in the work.