Caroms is something I make myself practice when training for a big money match. I play a game by myself where I try to carom the two balls and also send the first ball around to hit the cue ball again.
This really makes me get into controlling all three balls with a lot of creativity. I highly recommend this "training game" to anyone that wants to improve their touch and creativity.
That sounds like a tough exercise. Over here they play a carom game on the pool table that is not easy. They use it to gamble on a lot.
The game is called 357 I think. It is played with two like colors and one odd one. Typically the 3 and 11 and 1.
To score and get paid by all the other players you have to compete this sequence.
1. Carom the red and yellow or yellow and red.
2. Carom the two reds.
3. Carom all four.
Shoot until you miss.
If you scratch the turn is over. If you carom all four out of order then you pay a little amount into the table time pot. Make an object ball it spots on the center spot and it that isn't available then the head or foot spot.
Obviously the trick is to try to gather the balls on the first two shots so that the third is easier. Very tough game and the very best players in it will have you shaking your head with the way they are able to play off the second ball when going for the all-four carom.