Recommendation:

Pregame - inform the Coaches, Captains and Goalkeepers of the 8-Sec change.

Early in the game, educate the goalkeepers about the Law Change.

Once the goalkeeper has clear possession, start silent countdown* 8,7,6

Announce "Goalkeeper Ball in Play" or similar wording

Countdown*, raise and lower hand, verbally and with fingers 5,4,3,2,1

Stop play with a whistle

Restart with corner kick

* Both "Mississippi" and "thousand" are used as counting methods to approximate one second. "Five Mississippi, four Mississippi..." is a common way to count seconds,. "Five thousand, four thousand..." is another method used.