stretch your side split.
do the half side split stretch and the spread leg forward fold before you stretch the side split.
the side split should not be the first exercise in your stretching routine.
also check my workout plan for the side split. hand, i would glue a piece of elastic on the bottom of the tray that the dancer can slip their hand through to keep the tray from sliding. (if using a plastic tray you can slice the tray and attach the elastic that way. 