Even the replay booth takes a minute before making a call. You can too.

Taking a minute looks like hesitation when you are the one doing it. The people whose entire job is getting the call right treat that minute as part of the method, not as a failure of nerve. Speed and accuracy are different skills, and almost nothing you decide today actually requires the fast one.

Get yourself a line that buys time, something as plain as saying you want to think about it and will answer tonight. Use it once this week on a question you would normally answer in two seconds, such as whether you can cover a shift. Notice that nobody minds.