The wicketkeeper is the centerpiece of the fielding team. Make sure you keep ahead with the over rate, especially when you are playing T20 cricket where time is more of an issue. T20 cricket is a variety in which each side only gets 1 innings of 20 overs. Matches typically last only about 3 hours. Use your anticipation, concentration, and catching technique to stop runs when the bowler unintentionally makes a wild or wide delivery. Work together to prevent as many runs as you can and get your team in the lead. Try to make the batter feel that even if the bowler delivers a poor throw, you will always be there to catch it. That way, they are more likely to swing for every delivery and make a mistake that lets you get them out. The slips are the fielders behind the batsman on the offside of the field who are there to catch any balls beyond your reach. Decide if you need 2 or 3 slips, then help position them far enough away that you have room to dive and move but close enough that they will catch balls you cannot reach. This will take some practice to get the hang of, but once you know what your limitations are you will be able to help the slip fielders get into the perfect alignment to provide the extra coverage you need. Don't let anything get you down, not even a dropped catch. Fielders mostly take after the wicketkeeper's reactions, so it's very important to always keep up your energy levels and cheer the team on. This is especially important when your team is under pressure. As the center of the fielding team, you can influence everyone's performance by staying positive and offering encouragement.

Summary:
Set the tempo for the fielding on your team. Work together with the bowler to prevent runs. Help align the slip fielders on your team. Encourage your teammates.