Most people skip one of the most important steps when learning golf swing basics. Keeping focused throughout the game can make the difference between a great game and a bad one. If your mind is elsewhere, such as on being nervous, it isn't in the game.
It's normal to get upset when you have a bad shot. Get mad and get it out of your system. Before you step up to take your next swing you need to rid yourself of the anger and disappointment. That way you can focus on taking your next shot, stay in the moment.
You can learn a lot from the bad shots. You can see what it is that you did wrong, so that you can improve it for the next hole. There are some things you can try to work on your focus.
Hold your favorite pen in your hand. Focus on the tip of the pen. Try to block all other thoughts from your mind. The only thing you should see or think of is the tip of that pen. This can help you strengthen your focusing skills. It sounds silly, but it is very effective.
Meditation techniques can also be very useful in maintaining focus. Many players say that your focus is where the game is won or lost. If you can't focus on all of the different steps it takes to make the perfect shot, you very well may hit the ball into the trees. This is the number one golf swing basic to remember.