|First of all and you have probably done this already get them used to passing a ball accuratley between two players with no pressure of an opponent.
Simply line your players up in two lines facing their partner starting 5 yards away then increase to 10 yards then 15 etc..
Work on this until they can play fluently (not neccarsarilly all in one session) by using two touches. One touch to control it, one touch to pass it. Dont just encourage but insist they use one foot to trap and the other one to pass it. There is no excuse for one footed players and that can be nipped in the bud when young and around the age were talking here (under 8).
Advance this to one touch between the players.
Once they are comfortable then change it so one player stays still and passes either side of his partner who has to make a short 5 yard run to either his left or right and repeats the touch and pass as before.
Again advance this to one touch.
Move on to four cones and three players, with the players standing on a cone with one free cone.
The pass can only be made square (no diagonal) to a cone with a player on it to pass too and can not be passed back to the one who made the pass so it means the players have to keep moving around the grid to be an option.
This will help develop support play.
Then you could have three players in a triangle passing amongst themselves and add a defender so they are passing under pressure and at the correct angles, again use minimal 1 or 2 touches.
Any passing drill can be adjusted for any age group and for any desired outcome whether that be accuracy or speed of passing.