Ignore the Goalkeeper
The more pressure he feels, the longer the penalty taker fixates on the goalkeeper.
And the longer he fixates on the goalkeeper, the less his chance of scoring.
Wes Moss in his "Starting from Scratch," even asks entrepreneurs to "Underestimate the Obstacles."
I won't insult my readers' intelligence by explaining wider implications of this.
Brush off the Weight of any Expectations
This is self-explanatory.
Celebrate when You Score
If you celebrate "demonstratively," you increase your teammate's chance to score later in the shoot-out.
Simultaneously, you decrease the chance of the opposing player who is to score immediately after you.
The article doesn't say anything about how to mitigate this.
You may also see Target Fixation and Leadership the Sven-Gran Eriksson Way.