Bad shots are probably the number one reason teams lose games. It isn't that one team played a tough zone or a press, although these can be factors. It's not that one team was taller or faster, although these also contribute. But at the end of the day, these other factors are really just influencing the type of shots that teams are taking.
One of the biggest problems is that players often don't understand what a "good" shot is. This usually happens because their coaches don't teach their players what shots they should be taking. This is something that should be covered early and often, particularly with younger players.
So, what is a good shot? Well, that depends on a lot of things. It depends on the shooter. And the situation. And the philosophy of the coach. It also depends on the defensive coverage and if there is someone else open in a better spot. Lots of things go into determining is a shot is a good one or not.
Generally speaking, most teams want their best shooters shooting from spots where they are confident without being contested. The more often a team can achieve this, the more successful they will be. Sounds simple enough, but it rarely happens that way. In fact, if you ask most coaches or watch a few games, you will likely see shot after shot being made while contested or from players who are not ready to shoot.
As a player, it is imperative that you know what shots your coach is looking for. Perhaps that means layups first and then foul shots and open 3s. Maybe the coach wants shots from 15 feet. Coaches should take some time to clearly map out what shots the team is looking for and where they occur in the offense.
Following the trends and statistics from leagues around the world, layups (or other close shots like putbacks) are the most efficient way to score points, followed by foul shots and uncontested 3 pointers. This is a good starting point for both coaches and players in understanding where the best shots in the offense will come from. However, if the players are young, they may not have the strength to shoot 3s accurately, or at all. Again, there are many factors that will determine what a good shot is for each player and each team.
Whatever your skill level, determining what makes a good shot for your team is something that each player needs to figure out. Speak with your coach, find out what type of shot they want you to shoot. Practice these shots in your daily training so that you are ready to take these shots when the opportunity arises in games. You will find you score more points and win more games simply by shooting better shots.