look in their eye all the time they will usually look to a side after putting the ball or before the whistle.
also focus on yr run up, if they r right footed and their run up is straigh. they are shooting to yr left. if the run up has a wider angle or leaning more towards a side. they are shooting to yhe opposite direction. if the run up is too straight is a chip.
BUT IF THEY ARE OVER SELLING ON SIDE. they are going to do the exact opposite of everything I said