3D/4D Ultrasound tomorrow!!!!

we have our elective ultrasound tomorrow &I'm  so so excited!!! but I'm wondering...for the gender one we were told to eat something cold and sweet before we came in so he would cooperate which worked wonders. but for this one, should I do the same? or do you think we would get better pictures if he's sleeping or lazy versus trying to get him moving and risk not getting good shots?