Many free throw drills are repetition-style drills - stand at the foul line and shoot 2o foul shots. But since shooting foul shots in a game is a high pressure situation, and we really want to prepare our teams for the game, then some of our drills need to simulate that pressure. So, after players have been practicing free throws for a week or two, and you are reasonably confident they are making some progress, add in some free throw drills every now and again that require them to shoot under pressure.
I like to choose one of the following drills to end practice with every now and again. Since these drills have the risk of sprinting built in, and you don't want players exhausted in the middle of practice, I run these drills at the end.
The other advantage to doing this at the end of practice is that foul shots tend to be most crucial at the end of the game, when players are mostly spent - so they should be prepared to shoot in that situation.
You might also want to use something like Real Crowd Simulator to simulate crowd noise and prepare your players for what it would be like in a real game.
Note: This only gets one player shooting, which is definitely not optimal, but if you have run longer than expected or had a lot to get through in that practice, it is one way to get one of your players shooting under pressure and potential finish practice with a bit of sprinting.
Each player will take two foul shots. If the player:
Generally, as I mentioned above, I'll do the first drill if I'm pressed for time, and the second drill if I have 10 minutes or so to schedule at the end of the practice.
Some people will say you should not have the entire team pay for one player's mistakes. I believe that first off, they are a team, and as such they should be able to accept praise as a team when one person does something well, and accept punishment when one does something wrong. Nobody turns down the compliments.
And secondly, if a player is truly trying to make his foul shots, practicing and honestly attempting to improve, the team will know this and should be supportive. I've never had players upset about running suicides in these drills when they knew the shooter was seriously trying to improve - the only complaints have come when the shooter was goofing around, and then he deserved the criticism.
Players need to feel pressure in practice if they are to handle it during the game. These free throw drills are simple but do the job well. Use them often and push your players to focus on their shot and practice a good shooting routine.