Best thing to do is find a good instructor to help you. No amount of writing from us could equal a few hours with that instructor.
If that is not available, all I can say is concentrate on stance, grip, sight picture, breath control, trigger squeeze, follow through (the most often overlooked part).
Shoot slowly, not more than 50 shots at one session, or at least take a break of ten minutes each hour you are at the range. More often if you are the least bit tired. Practice, practice, practice, concentrating on all those factors. Look for flinching. Very important. Have someone watch you shoot. Have him tell you what he thinks of your technique. But be careful -- many want to be perceived as experts so they will give eroneous advice without either of you realizing it.
That's the best I can tell you without writing a book.
Cogito, ergo armatum sum