A lot of the time this is caused by leaning forward on take off, and not understand the concept that the chest goes up and then the heels drive over the head. I find layouts over an obstacle helps (a soft obstacle) so they must take off upwards.
I've generally found the best way around this is to rethink the progression towards a front layout
Tuck --> pike --> layout will generally give you a pikey layout that doesn't have the sort of forward travel you want for connection
Bounder --> Bounder over raised mats (say, about thigh level) --> Front layout will tend to give you a much better front layout.