I am basically a bogey golfer. I have been close to 9 or 10 hc at one point in my thirties, but it takes a lot of effort. If I could play a little more, I think I would be around 10. Of course if "ifs and buts were candies and nuts, we'd all have a happy Christmas!" I have been playing golf for around 40 years, so I will impart some "wisdom", or at least what I think I have learned.
If you haven't done so, take a lesson. There have been many self taught golfers, but many times what you think you are doing and what you are really doing are two different things. Golf is a difficult game, and it is harder if you aren't grounded in the fundamentals. Many adults may not be able to invest the time and money in weekly lessons, but a good lesson or two is better than none. Really, I think if you are older, it is better to space lessons out so that you have time to practice and integrate1 or 2 principles before changing something else. As adults, we are probably not wanting a coach to get us ready for the tour; we need some one to help us understand sound fundamentals and how we match up to that. The fundamentals to me, are grip, posture, alignment, balance, turn, plane, and tempo.
Practice with a purpose. When you first start, there is some merit to beating balls as long as you are beating them correctly. Even if you have proper grip, stance, alignment, plane, etc. , your timing and rhythm need development. If you regularly shoot around 90, then your practice needs to become more focused. It is ok to hit a few to loosen up, or even to hit a few when you can't play to keep your muscles toned, but when you are doing serious practice, you should have a goal in mind. When I am doing this, if I hit four or five the way I want, or even four out of five, I will stop and go putt. When I am practicing putting on the green, I am working on stroke, or distance, and line to a lesser degree. When I am practicing at home on the carpet, I am limited to about 10-15 feet, but when I hit about 3-5 that are "perfect", I quit. Of course carpet doesn' t have the same break or speed as the greens, but when I have putted about 10 minutes a day on the carpet in the week before a round, it is amazing how much better I putt on the course-and the same with chipping/pitching in the yard.
Clubs are a factor, and I believe you generally can play better with better clubs and clubs that fit you, but that doesn't necessarily mean new clubs. Quality clubs that are 3-4 years old can be had for a fraction of their new cost, if that is an issue. One thing that is sometimes overlooked by bogey golfers-I know I did it myself for years-is the condition of the grips. It doesn't matter if you have the newest Callaway or the cheapest Kmart special, you need your grips in good condition. Slick grips are difficult to control, and cause you to grip to hard trying which inhibits your swing. Find grips that fit you and change them before they get slick.
As others have said, loosen up and work on things on the range, and try to not do that when you are playing. Starting out that is hard, but try as best you can. Develop a routine that prepares you for your shot, doesn't take too long, and is repeatable. When you get over the ball, try to focus on the target, and on one swing thought. Freddie Couples once said," I take it back, I hit it, and that is as good as it gets." All of us don't have that ability or attitude, but that is kind of what you are striving for, especially on "stock" shots. A couple that work for me sometimes once I have lined up are, keep your head still and make a smooth back and through-then I go.
Also as others have said, plan a strategy that works to your strengths and stick with it. If you see things that you could do better, then work on those on the range/short game area. Try not to make major changes mid round--as Sam Snead said, "you gotta dance with who you brung".
From Mel Gibson in "The Patriot", "Aim small, miss small." On a straight 18 inch putt, aim for a blade of grass or a speck of dirt in the cup. It makes the hole bigger.
On putting, when I am over the ball , I have picked a line and committed. I concentrate on feel for the distance , making a smooth stroke down the line, and hitting the sweet spot .
Don't try to follow up a terrible shot with a brilliant shot. Pick a club you are confident in and a target you are comfortable reaching and make a good swing. Aim small and miss small.