What is the right footwork for a wicket keeper standing back to fast bowlers. Is it having the feet cross over behind each other as the keeper moves sideways or a shuffle where the feet following each other?
From memory as kids, we were taught to cross over the get extra distance, but a coach has mentioned to my son he should shuffle his feet as quick as possible

I always shuffled,it allows you to keep low and be in an athletic position to react to whatever may happen..fast feet head still as possible.

I’m don’t think there is a definitive “right footwork”.
I too was encouraged to use the cross over of the feet as it was suggested you’d get an extra half a yard reach to be in a better position to take the wider balls and catches.
I’ve also seen many high-quality keepers use the shuffle method and easily be in position to take the wider balls.
Irrespective of how your sons’ feet move standing back it’s important he works hard on getting strength into his legs as a powerbase. It’ll be his drive through the legs that will help him move more quickly and be in the right position to take the balls that make a difference to the team.
It’s equally as important to make sure your son works hard on training drills to stay on the balls of his feet and prevent being caught flat footed. As a keeper if you get caught being flat footed it makes it very difficult to push of the foot and have the leg drive to be in the right position to take the ball.
I hope this helps.

Great Question Xavier,
Like many, I was encouraged to cross over however depending on the situation the shuffle is also used. I don't believe there is a right or wrong. More what is natural for him!
Truly important is being able to maintain a power position (engaging quads and glutes, knees bent) whilst moving laterally. To gain maximum movement a powerful first movement is recommended this will enable you to push off the ball of your foot to get the really wide ones or take the diving hanger down legside. Practice and practice this a lot.

As a keeper of the current generation I have always ‘shuffled’ but whatever feels natural for Xavier will work. I find shuffling more efficient as you don’t get your feet caught up. The main take outs is that you maintain a ‘power position’ with knees bent and quads and glutes engaged. This comes from driving from the balls of your feet to enable yourself to move well laterally. This is developed through training drills where you have to use this method whilst also including catching the ball. A great reference would be to watch some footage of Brad Haddin back to the stumps. He brought lots of energy to his footwork which allowed him to get in the best position to catch the ball.