Some techniques that could be used to prepare a team for a penalty shoot out include;
Imagery: You can get the players to visualise the successful taking of the penalty kick. You can use audio recordings of the sounds of the crowd, the thumping of their heart & the referees whistle etc. to increase heart rate and the athletes level of anxiety.
Routines: It may be useful to put routines in places for the footballers to go through prior to the taking of a penalty kick, it would help them feel in control of the environment and may help control their levels of anxiety.
Finally, Pressure training would be a good tool. To try and replicate the exact environment is difficult obviously. Its impossible to replicate a penalty shoot out in the word cup final in training, and all the thoughts and feelings that go along with it. However you could use pressure training, by attempting to replicate the environment as closely as possible. I would suggest that maybe you could split the football team into two and the coach could give out punishments (extra training) for the losing team, or rewards (group dinner/ monetary) for the winning team, just to try and increase the pressure on the players.