As co-captain of my hockey team and vice captain of my cricket team i know what leadership is like, having captained in both, both being very different tactically....
The most important thing is to be loud. Very Loud. Don't hold back from belting out a loud "Well bowled Benno" or "It's not a library boys!" Encourage your teammates, even if they aren't doing as well as you would like.
Secondly, take risks. Your coach tells you one slip max. Use two, or even more if you feel like it. A captain can never fear failure, it's not an option.
Finally, enjoy yourself. When your strike bowler gets hit for his third four of the over don't drop your head and shake it, he's going to see it and this will make him feel even worse. Stay on your feet, stay loud and positive body language and a positive mindset is the key.
Good Luck!